OVERHEATING 500
Discussion
Went for my usual Sunday Blast, only to return home with a greeting of Steam from the engine.
It would appear that the expansion tank pipe released water onto the steaming hot manifolds & engine as the temperature gauge was up in the 120degrees.
For the first time in my ownership the electric fans did not kick in when the temperature started to exceed 90 degrees.
I must try fix the problem before Saturday.
Any suggestions? Is it likely to be the Cooling Fan Relays?
TVR expertise welcome!!!
It would appear that the expansion tank pipe released water onto the steaming hot manifolds & engine as the temperature gauge was up in the 120degrees.
For the first time in my ownership the electric fans did not kick in when the temperature started to exceed 90 degrees.
I must try fix the problem before Saturday.
Any suggestions? Is it likely to be the Cooling Fan Relays?
TVR expertise welcome!!!
take the two wires off the otter switch on the expansion tank and short them together(ignition on), if the fans spin up then your otter switch is dead, if not then check your fuse/fuses then the relay (they are all carefully wedged in with the battery and ecu)
>> Edited by apache on Tuesday 21st January 20:28
>> Edited by apache on Tuesday 21st January 20:28
Thanks for the two replies, both offering varying degree's of help.
Apache - thanks for your useful suggestion which I will try out later this week.
shpub - the obvious answer to your question of "why didn't I stop when it past 100degrees" was that I didn't notice it!!
Having had no previous overheating problems or not noticing any driving difference, I had no reason to check the guages as it was sitting @ the usual 90degrees while on the A roads. The last half mile home in slow traffic with fans obviously not working, caused the problem.
I usually keep my eye on all the guages, but in this instance was caught out.
Hope your gloomy prediction for my engine isn't right, as it was only boiling for a couple of minutes.
How often do you check yours?
Apache - thanks for your useful suggestion which I will try out later this week.
shpub - the obvious answer to your question of "why didn't I stop when it past 100degrees" was that I didn't notice it!!
Having had no previous overheating problems or not noticing any driving difference, I had no reason to check the guages as it was sitting @ the usual 90degrees while on the A roads. The last half mile home in slow traffic with fans obviously not working, caused the problem.
I usually keep my eye on all the guages, but in this instance was caught out.
Hope your gloomy prediction for my engine isn't right, as it was only boiling for a couple of minutes.
How often do you check yours?
If it turns out to be the fan fuse (and its my guess that is more likely than a dodgy otter) then it is probably worth checking if you've a wiring mod that fuses each fan independently. If you've not got it, and both are wired through the same fuse, might be worth considering.
Also, you can always carry round a paperclip to short the otter in case of emergencies. A couple of spare 40amp fuses in the glovebox are always welcome too.
Thing is, if you've a single fuse and it has blown, it may well have melted/welded itself into the fuse holder. When the 40a fuses go, they do tend to make a bit of a mess. So can be worth carrying round a pair of fine pointed plyers to get the debris out of the fuse holder.
I hope this ramble helps. I've been through pretty much every cooling fix there is in my Griff and now it runs at 80 degrees, rain, sun, shine, snow whatever. So worth fixing for peace of mind.
AF
Also, you can always carry round a paperclip to short the otter in case of emergencies. A couple of spare 40amp fuses in the glovebox are always welcome too.
Thing is, if you've a single fuse and it has blown, it may well have melted/welded itself into the fuse holder. When the 40a fuses go, they do tend to make a bit of a mess. So can be worth carrying round a pair of fine pointed plyers to get the debris out of the fuse holder.
I hope this ramble helps. I've been through pretty much every cooling fix there is in my Griff and now it runs at 80 degrees, rain, sun, shine, snow whatever. So worth fixing for peace of mind.
AF
How often do you check yours?
Sorry for being a bit direct but this was the third my car reached meltdown temps I have had to deal with today. When I suggested that they stopped the car when it started getting warm, I was greeted with silence. I was then told that there was no need to as the car was covered under warrenty...
As for watching... In the Griff like a hawk. Caught a head gasket going that raised the temp by about 10 degrees. Left longer and I would have needed new cylinder heads at £2000 each... just got into the habit of checking becuase I know what can happen if you don't.
In the 520 there is an monitoring system that triggers if pressures drop, temps increase etc etc.
Apache covered the first things to do. Check the otter switch. Then fuses and relays. Many people fit fan overrides so that if the otter switch dies, they can turn on the fans manually and save the day. Details in the bible or get the Mod Wise kit.
PS if it is a 40 AMP fuse, then Demon Tweeks or a TVR Dealer are about the only places where you can get them.
>> Edited by shpub on Wednesday 22 January 08:28
shpub said:
PS if it is a 40 AMP fuse, then Demon Tweeks or a TVR Dealer are about the only places where you can get them.
>> Edited by shpub on Wednesday 22 January 08:28
Or, there's a dodgy looking guy with a stall on Hatfield market who sells what looks like parts he's collected off cars the night before. He seems to have boxes of 40 amp blade fuses...
Otter switches can fail (I think I'm on my 3rd in 2 years) so I would recommend at least making an over-ride cable and carrying it with you. A better answer is to fit a fan over-ride, but if you don't want to get the hands dirty to.....
Get a thickish piece of braided cable (say 3-4 inches long) and crimp a male spade connector on each end like the ones at the back of the otter switch. If you get stuck somewhere and you suspect the otter switch has gone, pull off the 2 wires and use the made up cable as an "always on" switch. It'll get you home or to a garage. Paper clips can be used as a Blue Peter style alternative.
DT
Get a thickish piece of braided cable (say 3-4 inches long) and crimp a male spade connector on each end like the ones at the back of the otter switch. If you get stuck somewhere and you suspect the otter switch has gone, pull off the 2 wires and use the made up cable as an "always on" switch. It'll get you home or to a garage. Paper clips can be used as a Blue Peter style alternative.
DT
shpub said: If the temp was 120 why didn't you stop earlier when it was hitting 100?
That is potentially "head warping oh dear I have scrapped the engine" temperature...
Steve - This happened to me when I first got the Griff. It regularly went up to 110 degrees in traffic. When I asked the service department at the dealers where I bought the car I was told "Not unusual sir". This was repeated to me on at least 2 occasions. Of course, I know now that is complete bollox and TVR were rather annoyed that I had been given poor advice, especially from a main dealer.
It was of course, the otter switch, probably too high rated as the fans would kick in, but not until 100-110. TVR replaced it and it was fine, running at 90 max until that switch failed in a "once on, I'll stay on" position. Then the fans seemed to kick in at 60-65 and stay on - temp would never get above 75ish. Occasionaly it behaved as you would expect but as it was summer and I was doing mostly slow traffic driving I left it as it was. I think they changed it again at it's 18k service because it works to spec now.
DT
shpub said:
As for watching... In the Griff like a hawk. Caught a head gasket going that raised the temp by about 10 degrees. Left longer and I would have needed new cylinder heads at £2000 each... just got into the habit of checking becuase I know what can happen if you don't.
>> Edited by shpub on Wednesday 22 January 08:28
Agreed. I glance at all the gauges every couple of minutes. This paranoia is the result of spending the last few years on the TVRCC mailing list and Pistonheads listening to all the things that can go wrong. I should imagine you'll be watching them closer in the future!
I believe you can get the heads pressure (compression?) tested which will show if you have indeed warped the heads or blown the head gaskets. Assuming all is OK, I agree with the recommendations about the otter switch and fan fuses.
I have also installed a manual fan override switch and a warning LED. I used two bi-colour LEDs (one per fan) which show green when the fan is spinning and red when the override switch is activated. This allowed me to spot when one of my fan fuses failed (one of the two LEDs lit) and also when the otter switch failed (temperature high, fans not running). Not to difficult to install.
All details in the Griffith and Chimaera bible (do I get commission yet Steve?).
Ian A.
Had my Griffith for over a year now and no overheating problems I'm pleased to say....2 basic questions however
1) I keep a short lenghth of cable with male connectors as described by "donatien" if I need to effect this temporary repair , will I fit this with ignition on ? off? battery connected ? etc as you can tell I have a fear of being part of a live circuit whilst fiddling with the unknown.
2) The sensible plan seems to be to fit an override switch as mentioned on this and various threads, is this procedure described anywhere in idiot proof terms, or can someone suggest who can do this and importantly how much.
M J H said:
1) I keep a short lenghth of cable with male connectors as described by "donatien" if I need to effect this temporary repair , will I fit this with ignition on ? off? battery connected ? etc as you can tell I have a fear of being part of a live circuit whilst fiddling with the unknown.
.
Best to turn engine and ignition off, no need to disconnect battery. Engine off, saves you from catching anything in the fan/serpentine belt, and overheating stationary engine. Connect wires and secure away from rotating /hot parts.
I like it. I've just got the boring old on-off fan override switch and a lower temperature otter switch & matched thermostat. Wish I had ultra cool bi-colour LEDs though. Much respect.
IPAddis said:I used two bi-colour LEDs (one per fan) which show green when the fan is spinning and red when the override switch is activated. This allowed me to spot when one of my fan fuses failed (one of the two LEDs lit) and also when the otter switch failed (temperature high, fans not running).
2) The sensible plan seems to be to fit an override switch as mentioned on this and various threads, is this procedure described anywhere in idiot proof terms, or can someone suggest who can do this and importantly how much.
Tis in the bible or get the Modwise kit.
Steve
www.tvrbooks.co.uk
The Griff 500 heads are pretty high up the tuning scale with lots of nice work on them. They are not cheap.
Typical cost to replace them is around 4-5 grand so work it out from there. Assuming that both are totally scrapped and includes all the new gaskets stretch cyl head bolts etc.
Just making people aware of the possible consequences of letting their engines overheat and ignoring any "my engine doesn't normally do that" type of problem.
Steve
Typical cost to replace them is around 4-5 grand so work it out from there. Assuming that both are totally scrapped and includes all the new gaskets stretch cyl head bolts etc.
Just making people aware of the possible consequences of letting their engines overheat and ignoring any "my engine doesn't normally do that" type of problem.
Steve
KeithS said:
shpub said:
new cylinder heads at £2000 each...
>> Edited by shpub on Wednesday 22 January 08:28
Two grand??????? Bloody hell, I'm frightened to drive mine now.......
Why 2 grand? Each?
To make you feel better , it is quite rare for heads to need replacing, and you can get a much better price , Steve is correctly quoting TVR prices for brand new factory replacements inc fitting.
You can get brand new Stage 3 heads for about £1100 +VAT pair (recon £750) these would be as good as the 500 ones. so fitted with VAT under 2 grand.
Tim
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