Mobile inspection to include compression/leakdown test?
Discussion
Evening lads,
I'm going to ring around in the morning but just wondered if any of the Porsche inspectors, such as Peter Morgan, can carry out a compression/leakdown test on a 964 at the sellers address.
Find out tomorrow if I can have the car. If so, it's in the Midlands and I'm in Newcastle so I would like to instruct an inspection, then just go and collect it, if it checks out ok.
Thanks in advance!
I'm going to ring around in the morning but just wondered if any of the Porsche inspectors, such as Peter Morgan, can carry out a compression/leakdown test on a 964 at the sellers address.
Find out tomorrow if I can have the car. If so, it's in the Midlands and I'm in Newcastle so I would like to instruct an inspection, then just go and collect it, if it checks out ok.
Thanks in advance!
Hopefully the latter of those choices Craig.
May not come off yet. Someone in line before me, but he has been stalling for over a week, so seller is going to ring him tomorrow, then ring me.
Engine was rebuilt but 40k miles ago (at only 60K!) so I want that test for peace of mind. The owner is busy with builders at his house and all sorts so simply can't take it across town for an inspection, etc. He's happy for an inspector to visit him though.
ETA - Not track spec yet. Just a nice clean road car... I hope. The mods will come but over time.
May not come off yet. Someone in line before me, but he has been stalling for over a week, so seller is going to ring him tomorrow, then ring me.
Engine was rebuilt but 40k miles ago (at only 60K!) so I want that test for peace of mind. The owner is busy with builders at his house and all sorts so simply can't take it across town for an inspection, etc. He's happy for an inspector to visit him though.
ETA - Not track spec yet. Just a nice clean road car... I hope. The mods will come but over time.
Well I never!
Given that the standard P'heads answer to every "What do you think of this car?" thread is "Get a PPI done", I'm amazed that no-one actually knows if they do a compression test during a PPI.
Obviously not as interesting as talking about depreciation.
Well I've just rang and they don't at Peter Morgans, for anyones future reference.
Given that the standard P'heads answer to every "What do you think of this car?" thread is "Get a PPI done", I'm amazed that no-one actually knows if they do a compression test during a PPI.
Obviously not as interesting as talking about depreciation.
Well I've just rang and they don't at Peter Morgans, for anyones future reference.
I knew that (honestly I did!).
Where in the midlands is the car? One of the local specialists may go out to it.
If the engine rebuild was done by a specialist I'm sure all will be fine as they will have carried out the modifications to stop the problem arising so quickly again, but for the sake of a coupe of hundred quid do have the check done.
Where in the midlands is the car? One of the local specialists may go out to it.
If the engine rebuild was done by a specialist I'm sure all will be fine as they will have carried out the modifications to stop the problem arising so quickly again, but for the sake of a coupe of hundred quid do have the check done.
Doing a Compression test and leak down on a 996 especially the Turbo would take for ages and be very expensive in Labour.
There was an old fashioned electrical way to do it using the portable electronic tuners. You would crank the car over with the fuel pump fuse removed and the computer ( having already been told the exact model) could measure the increase and decrease in cranking current to determine an approximate value for cylinder balance. No figures just a percentage balance. It also could tell if the engine was too easy to crank, lower than expected total compression on all the cylinders.
I'm sure modern tuners are even better at it now. When I was Chairman of Neptune Car Maintenance Facility we had a "Sun Tune 1990 but we got shut because of the new CO requirement instead of HC for MOT's.
I some times use Durametrics , you can shut down each cylinder at a time. Its not just good for checking which cylinder is not firing, but if you have a good ear you can tell which cylinder responds differently. Its not fool proof and wont give you a figure but you can work out which cylinders are firing weak.
There was an old fashioned electrical way to do it using the portable electronic tuners. You would crank the car over with the fuel pump fuse removed and the computer ( having already been told the exact model) could measure the increase and decrease in cranking current to determine an approximate value for cylinder balance. No figures just a percentage balance. It also could tell if the engine was too easy to crank, lower than expected total compression on all the cylinders.
I'm sure modern tuners are even better at it now. When I was Chairman of Neptune Car Maintenance Facility we had a "Sun Tune 1990 but we got shut because of the new CO requirement instead of HC for MOT's.
I some times use Durametrics , you can shut down each cylinder at a time. Its not just good for checking which cylinder is not firing, but if you have a good ear you can tell which cylinder responds differently. Its not fool proof and wont give you a figure but you can work out which cylinders are firing weak.
Thanks Mr.Cooke,
Don't know exactly where it is, I was going to go down this weekend but figured it'll cost me £100 in petrol plus a day of my time and there's still this other buyer involved which I'm waiting to hear about. Easier to pay another couple of hundred to an inspector and take it from there.
60K is early for a rebuild, so I want to know what went wrong and get the comp. check done. The car is an early one with the old barrels etc.
At the moment I can't find an inspector so may end up leaving it. I actually know of a lovely C4 that I've had pics sent through of. It sounds like the better car to be honest, having had suspension changed, engine rebuild, cup mirrors. Lots of little things that add up. I'm struggling to get past the C4 thing though and think I'll regret not waiting for a C2 once the novelty of a new toy has worn off.
I'll post back on any developments. Thanks.
ETA - Hi ras and Frank,
yep I would prefer a proper garage inspection but the car is now out of tax and his insurance is on his new car.
Frank - yep I thought there was maybe a quicker way of doing the leakdown test now but was just guessing.
It's looking like a ball-ache to be honest
and while they're rare-ish now I don't need a car til spring so have 4 months...
ras - C2 manual coupe. Up for £17k agreed on £15250 now. Do a bit of digging and you'll guess which car but I'm keeping schtum until I know if I'm going ahead.
Don't know exactly where it is, I was going to go down this weekend but figured it'll cost me £100 in petrol plus a day of my time and there's still this other buyer involved which I'm waiting to hear about. Easier to pay another couple of hundred to an inspector and take it from there.
60K is early for a rebuild, so I want to know what went wrong and get the comp. check done. The car is an early one with the old barrels etc.
At the moment I can't find an inspector so may end up leaving it. I actually know of a lovely C4 that I've had pics sent through of. It sounds like the better car to be honest, having had suspension changed, engine rebuild, cup mirrors. Lots of little things that add up. I'm struggling to get past the C4 thing though and think I'll regret not waiting for a C2 once the novelty of a new toy has worn off.
I'll post back on any developments. Thanks.
ETA - Hi ras and Frank,
yep I would prefer a proper garage inspection but the car is now out of tax and his insurance is on his new car.
Frank - yep I thought there was maybe a quicker way of doing the leakdown test now but was just guessing.
It's looking like a ball-ache to be honest
and while they're rare-ish now I don't need a car til spring so have 4 months...ras - C2 manual coupe. Up for £17k agreed on £15250 now. Do a bit of digging and you'll guess which car but I'm keeping schtum until I know if I'm going ahead.
Edited by marky911 on Saturday 21st January 11:05
I could have told you PM wouldn't do a compression or leak down test 
It's not really his modus operandi. No doubt he could "arrange" one but that's hardly the same.
Find a respected indy close to the vendor and get the car over there. Depending on just where the car is in the Midlands, PCT would be my choice.
It's not really his modus operandi. No doubt he could "arrange" one but that's hardly the same.Find a respected indy close to the vendor and get the car over there. Depending on just where the car is in the Midlands, PCT would be my choice.
Cheers Slippy,
Yeah it appears, Peter Morgan and to be fair most others like him probably, can only check the things you can check yourself, if you have a bit of common sense.
He doesn't remove the undertray or anything. I can check, panels, brakes, tyres, rust prone areas, paperwork etc, so I'm not paying £350 for that. The most important thing (besides rust) on a 964 as I'm sure you know, is the engine. That's my main priority.
Will contact PCT if that becomes an option, thanks for the suggestion.
Yeah it appears, Peter Morgan and to be fair most others like him probably, can only check the things you can check yourself, if you have a bit of common sense.
He doesn't remove the undertray or anything. I can check, panels, brakes, tyres, rust prone areas, paperwork etc, so I'm not paying £350 for that. The most important thing (besides rust) on a 964 as I'm sure you know, is the engine. That's my main priority.
Will contact PCT if that becomes an option, thanks for the suggestion.
marky911 said:
60K is early for a rebuild, so I want to know what went wrong and get the comp. check done. The car is an early one with the old barrels etc.
It's not really that early for such a car, it depends on the type of mileage driven.I've seen them with 30%+ losses on a couple of cylinders at 30k miles and with perfectly healthy matching losses across all six pots at 150k miles.
IME many early cars are pretty far gone by 80k miles. But this said, a local chap to me bought one new in 1990, drove it every day for 250,000 miles and neither the engine or box ever came apart.
Hence the need for the test really.
Mark, a leakdown test would take a couple of hours labour and has the benefit of showing where the problem is i.e piston ring or inlet/exhaust valves. Saying this a good indi experienced in this engine would pick up problems without resorting to a leakdown, and I would rather have an experienced indi look rather than an inexperienced guy with a leakdown...if you get my drift. Smoke, high emissions, general running, test drive etc.
Most engines will have some oil leaks but dont get too hung up on the engine, Rust repairs, engine tinware, tired suspension, clutch, tyres will all consume 000's if they need to be replaced. My car was rebuilt by Porsche at 55k miles, but that was 10 years+ ago and as such I find the point totally irrelevant.
I think I know of the car in question, black? Check how much has been spent on it the last couple of years.
Most engines will have some oil leaks but dont get too hung up on the engine, Rust repairs, engine tinware, tired suspension, clutch, tyres will all consume 000's if they need to be replaced. My car was rebuilt by Porsche at 55k miles, but that was 10 years+ ago and as such I find the point totally irrelevant.
I think I know of the car in question, black? Check how much has been spent on it the last couple of years.
Yep ras, that's the one.
Edited - Car gone so irrelevant.
I know what you mean about rebuilds etc. There are loads of factors to consider. One thing I believe is that ALL 964s require a rebuild at some point before 130K. I know of a couple of cars that have made it past that, but I also know of LOTS that haven't made it to 100K, so this aswell as rust are the main worries, but I totally agree, 964s make very good wallet-hoovers, so suspension, brakes etc are all a bonus.
Also as Mr.C says above, some engines lose a lot over a couple of pots. Sometime there are no signs, excessive smoking, misfire, etc, but the car maybe just down on power and even that can be hard to assess if you haven't driven many lately.
Anyway, I've just popped in for some lunch. Off to continue with my DIY. Cheers.
Edited - Car gone so irrelevant.
I know what you mean about rebuilds etc. There are loads of factors to consider. One thing I believe is that ALL 964s require a rebuild at some point before 130K. I know of a couple of cars that have made it past that, but I also know of LOTS that haven't made it to 100K, so this aswell as rust are the main worries, but I totally agree, 964s make very good wallet-hoovers, so suspension, brakes etc are all a bonus.
Also as Mr.C says above, some engines lose a lot over a couple of pots. Sometime there are no signs, excessive smoking, misfire, etc, but the car maybe just down on power and even that can be hard to assess if you haven't driven many lately.
Anyway, I've just popped in for some lunch. Off to continue with my DIY. Cheers.
Edited by marky911 on Saturday 21st January 14:31
I quietly hamper after a late model 964 C4, I've already owned a 91 C2 previously.
I would be more interested in rust these days on especially early 964s, I've heard (from a very well respected Indy) that on alot of cars if you push hard enough on the metal under the windscreen your hand could go through. Yet visually they seem fine.
Where exactly you pushed he did not say or (I was so gobsmacked when he said it) I've forgot,
but I'm guessing under the wing against the bulkhead.
I would be more interested in rust these days on especially early 964s, I've heard (from a very well respected Indy) that on alot of cars if you push hard enough on the metal under the windscreen your hand could go through. Yet visually they seem fine.
Where exactly you pushed he did not say or (I was so gobsmacked when he said it) I've forgot,
but I'm guessing under the wing against the bulkhead.marky911 said:
Cheers Slippy,
Yeah it appears, Peter Morgan and to be fair most others like him probably, can only check the things you can check yourself, if you have a bit of common sense.
He doesn't remove the undertray or anything. I can check, panels, brakes, tyres, rust prone areas, paperwork etc, so I'm not paying £350 for that. The most important thing (besides rust) on a 964 as I'm sure you know, is the engine. That's my main priority.
Will contact PCT if that becomes an option, thanks for the suggestion.
Not sure if thats true with the undertray part... On a 964 993 i remove untray etc whether inspection through Peter Morgan or through my own company, mobile or workshop inspection and pretty sure rest of the guys working through Peter would do this also..Nothing can really be seen underneath unless you remove it.Yeah it appears, Peter Morgan and to be fair most others like him probably, can only check the things you can check yourself, if you have a bit of common sense.
He doesn't remove the undertray or anything. I can check, panels, brakes, tyres, rust prone areas, paperwork etc, so I'm not paying £350 for that. The most important thing (besides rust) on a 964 as I'm sure you know, is the engine. That's my main priority.
Will contact PCT if that becomes an option, thanks for the suggestion.
As per leakdown test that would have to be done at the workplace as it would not be the most ideal job to be doing as mobile service,i.e tools/equipment extra time required etc
Edited by stup on Saturday 21st January 18:34
The 964 is a great car but, like any car, needs an inspection before buying.
We repair a lot of 964 and 993 models and buying a bad or one that needs work can be very expensive.
Any car needs to have documented history of what was done, when and why.
I recently saw a very clean 1989 C4 with corroded through windshield surround. This is rare in the Pacific Northwest as cars don't rust here. Of course, the water leaked into the alarm module.....
We recently replaced the crankcase through bolt seals on an extremely clean 47K mile 1990 964 C2.
Excessive amount of oil was leaking onto the garage floor, engine was faultless apart from that.
We repair a lot of 964 and 993 models and buying a bad or one that needs work can be very expensive.
Any car needs to have documented history of what was done, when and why.
I recently saw a very clean 1989 C4 with corroded through windshield surround. This is rare in the Pacific Northwest as cars don't rust here. Of course, the water leaked into the alarm module.....
We recently replaced the crankcase through bolt seals on an extremely clean 47K mile 1990 964 C2.
Excessive amount of oil was leaking onto the garage floor, engine was faultless apart from that.
stup said:
Not sure if thats true with the undertray part... On a 964 993 i remove untray etc whether inspection through Peter Morgan or through my own company, mobile or workshop inspection and pretty sure rest of the guys working through Peter would do this also..Nothing can really be seen underneath unless you remove it.
As per leakdown test that would have to be done at the workplace as it would not be the most ideal job to be doing as mobile service,i.e tools/equipment extra time required etc
Hi Stu. I rang Peter Morgans this morning and spoke to a woman who told me they can't take the undertray off as the car is not theirs or something along those lines. I'm guessing incase they couldn't get it back on or something? Must admit I found it very strange! As per leakdown test that would have to be done at the workplace as it would not be the most ideal job to be doing as mobile service,i.e tools/equipment extra time required etc
Edited by stup on Saturday 21st January 18:34
Fully understand the problems with a roadside leakdown test though.
Basically going off the conversation I had, the inspection on offer does not offer me anything I couldn't confidently do myself, apart from trailing to the location for me.
Anyway, I hope business is booming. I've still not been up with the 964T but I feel the bodywork has now got to take priority to get the old girl back upto a standard I'm happy with. Reverting to standard boost again until I can get it up to you one day in the probably quite distant future.
Wozy68 said:
I quietly hamper after a late model 964 C4, I've already owned a 91 C2 previously.
I would be more interested in rust these days on especially early 964s, I've heard (from a very well respected Indy) that on alot of cars if you push hard enough on the metal under the windscreen your hand could go through. Yet visually they seem fine.
Where exactly you pushed he did not say or (I was so gobsmacked when he said it) I've forgot, but I'm guessing under the wing against the bulkhead.
Evening Wozy,I would be more interested in rust these days on especially early 964s, I've heard (from a very well respected Indy) that on alot of cars if you push hard enough on the metal under the windscreen your hand could go through. Yet visually they seem fine.
Where exactly you pushed he did not say or (I was so gobsmacked when he said it) I've forgot,
but I'm guessing under the wing against the bulkhead.well the next car on my list is a C4, I'm not getting impatient but this car I know of sounds like a really well cared for car. Have just emailed the guy back. Spoke to him last week. I was hell-bent on a C2 but this C4 is too good to pass by without checking it out. I have never owned a 4wd car let alone a 964. It will be for regular use in all weathers from spring til Autumn so a 4 maybe a benefit.
If I don't get on with it I can always sell it.
Is your CS on sale or return somewhere? Can't remember where now but I saw a white one in the classifieds the other night.
Good luck with the sale anyway, It looks stunning.
sportsandclassic said:
We have done a few 964 rebuilds and mainly for oil leaks but once apart we have found that piston rings are worn very thin and require replacement, this has been as low as 60000 miles.
Hi Mike, yep they're so inconsistent too, mileage wise. This C4 has had a rebuild and clutch 20K ago but is bone dry I'm assured and there is a good indy close to it ready to do the tests I want. Off topic - I spoke to you before Xmas when I was considering Eamonns 993. I was meant to get back to you just to say how I got on. I spoke to Eamonn and he was very honest about the car. Hence I didn't buy it. I bought my first DA machine off him though so he at least scored for something.
I appreciated his honesty. Nice guy. He basically said stick with my Turbo.D900SP said:
The 964 is a great car but, like any car, needs an inspection before buying.
We repair a lot of 964 and 993 models and buying a bad or one that needs work can be very expensive.
Any car needs to have documented history of what was done, when and why.
I recently saw a very clean 1989 C4 with corroded through windshield surround. This is rare in the Pacific Northwest as cars don't rust here. Of course, the water leaked into the alarm module.....
We recently replaced the crankcase through bolt seals on an extremely clean 47K mile 1990 964 C2.
Excessive amount of oil was leaking onto the garage floor, engine was faultless apart from that.
Totally agree with you. I've had a C2 before my 964T. Had to have the motor rebuilt on the 964T but it was right on the miles for it to be honest at 98K. Love it though and have started realising just how nice it is, since I set out on my search for another Carrera.We repair a lot of 964 and 993 models and buying a bad or one that needs work can be very expensive.
Any car needs to have documented history of what was done, when and why.
I recently saw a very clean 1989 C4 with corroded through windshield surround. This is rare in the Pacific Northwest as cars don't rust here. Of course, the water leaked into the alarm module.....
We recently replaced the crankcase through bolt seals on an extremely clean 47K mile 1990 964 C2.
Excessive amount of oil was leaking onto the garage floor, engine was faultless apart from that.
You guys are spoilt in the USA.
Even seventies 911s that haven't been particularly pampered are still totally original. It must be great!
I love American muscle cars too and you still have immaculate ones of those lying around.
Anyway, thanks for the advice everyone. I'll see how I get on with this C4 anyway.
I'd like to apologise for what appears to have been a somewhat confused message from our office. The bottom line was right (we don't do compression tests in the field), but the middle bit needs further explanation.
We don't do mobile compression tests because that would expose us to liability from the seller (with whom we have no agreement or contract of service) if the car subsequently developed or was claimed to have developed an issue.
If you can persuade a seller to take a car to a service shop for tests, and the buyer is paying, I would suggest the proprietor should ensure that the seller accepts liability for any issues found or arising subsequently before any work is done.
It would take at least an hour to do a compression or leak down test properly and that would be outside the scope of the our regular inspection. We have considered offering this as an optional service, but decided it wasn't worth it. For the same reason we don't do boroscope checks on the water cooled cars. I think that was the message that somehow became garbled when you rang our office. Nevertheless, and as noted in this thread, I would like to think that most times I can spot signs of a broken head stud without having to resort to a compression check. I'm not infallible of course, but if I saw the warning signs I would probably advise the client to walk away anyway. And corrosion is indeed as much of a problem on these cars as engine issues.
We do remove the undertrays on the 964 - and it's a real pain in the neck - all those 10mm nuts and bolts. As Stuart says, you can't assess the underside of a 964 without doing this. Again, apologies if this message didn't get across.
I might add that we've been doing inspections for a very long time and I personally have over 35 years experience of working with Porsches. We can claim to have a certain level of experience in spotting the good from the not so good and many of the better specialists respect us for that.
We don't do mobile compression tests because that would expose us to liability from the seller (with whom we have no agreement or contract of service) if the car subsequently developed or was claimed to have developed an issue.
If you can persuade a seller to take a car to a service shop for tests, and the buyer is paying, I would suggest the proprietor should ensure that the seller accepts liability for any issues found or arising subsequently before any work is done.
It would take at least an hour to do a compression or leak down test properly and that would be outside the scope of the our regular inspection. We have considered offering this as an optional service, but decided it wasn't worth it. For the same reason we don't do boroscope checks on the water cooled cars. I think that was the message that somehow became garbled when you rang our office. Nevertheless, and as noted in this thread, I would like to think that most times I can spot signs of a broken head stud without having to resort to a compression check. I'm not infallible of course, but if I saw the warning signs I would probably advise the client to walk away anyway. And corrosion is indeed as much of a problem on these cars as engine issues.
We do remove the undertrays on the 964 - and it's a real pain in the neck - all those 10mm nuts and bolts. As Stuart says, you can't assess the underside of a 964 without doing this. Again, apologies if this message didn't get across.
I might add that we've been doing inspections for a very long time and I personally have over 35 years experience of working with Porsches. We can claim to have a certain level of experience in spotting the good from the not so good and many of the better specialists respect us for that.
marky911 said:
Also as Mr.C says above, some engines lose a lot over a couple of pots. Sometime there are no signs, excessive smoking, misfire, etc, but the car maybe just down on power and even that can be hard to assess if you haven't driven many lately.
They don't necessarily lose power either. My race car (964 C2 - standard engine) was smoking a bit on start up towards the end of the 201 season - upon a leakdown test 2 cylinders were showing leakage of 25% and 28%. I had a spare engine but even changing that over was near impossible before the next meeting (the induction system needed changing and when running it would need mapping too), so off I went to the rolling road to test the power - within 1bhp of where it had been before the season started. I went to the next meeting, got pole and won both races.The leakage was checked straight afterwards, with a bit more head-scratching given the power was still there. The normal leakage was the same, but when checked at BDC (bottom dead centre) rather than the usual TDC (top dead centre) there was normal minimal leakage. QED, the bores had gone oval at the top.
This is more significant as it means the barrels and pistons needed replacing (£3000 or so just for the parts). It had been noted when it was rebuilt in January 2009 that this would be the case next time it was rebuilt.
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