bent conrod

Author
Discussion

philpalmer

Original Poster:

174 posts

216 months

Tuesday 1st December 2009
quotequote all
Hi there

I recently bought a car from ebay for my daughter. (private seller / paid using paypal)

Everything seemed fine except there was a vibration when I started the engine.

I took the car to a local garage for a service and asked them to check out the vibration problem.

They first said it could be the cambelt but have now said its likely to be a bent conrod.

As its ebay / private sale I seem to have no comeback so this car is turning into a nightmare. It was only £1000 but to me this is quite a bit of money.

Any idea of the cost to fix. The car is a 1998 Seat Arosa 1.7 SDI.
I guess the other option is a replacement engine. That doesn't sound much fun either.

I feel sick.

Thanks for any replies

Phil



stevieturbo

17,229 posts

246 months

Tuesday 1st December 2009
quotequote all
philpalmer said:
Hi there

I recently bought a car from ebay for my daughter. (private seller / paid using paypal)

Everything seemed fine except there was a vibration when I started the engine.

I took the car to a local garage for a service and asked them to check out the vibration problem.

They first said it could be the cambelt but have now said its likely to be a bent conrod.

As its ebay / private sale I seem to have no comeback so this car is turning into a nightmare. It was only £1000 but to me this is quite a bit of money.

Any idea of the cost to fix. The car is a 1998 Seat Arosa 1.7 SDI.
I guess the other option is a replacement engine. That doesn't sound much fun either.

I feel sick.

Thanks for any replies

Phil
Unless the garage have stripped the engine down....I'd REALLY like to know how they have assessed it as a bent conrod.

Might be worth taking it to a more experienced garage.

ringram

14,700 posts

247 months

Tuesday 1st December 2009
quotequote all
Dodgy or badly fitted balancer?

HRG

72,857 posts

238 months

Tuesday 1st December 2009
quotequote all
stevieturbo said:
philpalmer said:
Hi there

I recently bought a car from ebay for my daughter. (private seller / paid using paypal)

Everything seemed fine except there was a vibration when I started the engine.

I took the car to a local garage for a service and asked them to check out the vibration problem.

They first said it could be the cambelt but have now said its likely to be a bent conrod.

As its ebay / private sale I seem to have no comeback so this car is turning into a nightmare. It was only £1000 but to me this is quite a bit of money.

Any idea of the cost to fix. The car is a 1998 Seat Arosa 1.7 SDI.
I guess the other option is a replacement engine. That doesn't sound much fun either.

I feel sick.

Thanks for any replies

Phil
Unless the garage have stripped the engine down....I'd REALLY like to know how they have assessed it as a bent conrod.

Might be worth taking it to a more experienced garage.
Measure the stroke with a DTI through the plug hole?

Pumaracing

2,089 posts

206 months

Tuesday 1st December 2009
quotequote all
Why on god's earth would a conrod be bent? The only conceiveable way is if the engine was driven through a flood, sucked in water and hydraulic locked but I doubt if it would run at all after that.

It could just be an engine or gearbox mount which is far more likely but frankly for the grand you paid for it if it runs, doesn't conk out for no apparent reason and uses a normal amount of fuel just run the bloody thing and leave it alone.

Boosted LS1

21,167 posts

259 months

Wednesday 2nd December 2009
quotequote all
Is that a dismall or petrol engine? It could be anything effecting fuelling or spark, causing a misfire of sorts. A whole host of simple things could cause an issue like this. You could take it to a rolling road and have them hook it up to a tuner.

philpalmer

Original Poster:

174 posts

216 months

Wednesday 2nd December 2009
quotequote all
Thanks for the replies.
its a 1.7 sdi engine.

As its for my daughter I want a car thats going to be reasonably reliable as we live in the sticks.
I should find out later today the estimate for repair.

Andoo

226 posts

172 months

Wednesday 2nd December 2009
quotequote all
Not sure if that year of car woudl have a dual mass flywheel or not, but if so it could be that!

My Laguna suffered from vibration just as the clutch was wearing out and dual mass flywheels are known for that.

However, as suggested it's probably more likely to be a knackered rubber mount as it is possible an 11 year old car would have had diesel spilled on the rubber which will cause it to break down.

Or, someone suggested the balancer. Not sure this engine had one, but it's a possibility too....

Another possibility is the injectors are gummed up which could cause a bit of vibration as the engine isn't getting the fuel delivery it requires. If the car was used mostly round town it is likely they need cleaned. Look for a Bosch agency in your area and ask how much (in fact, they would give you a better idea of what may be wrong).

Pumaracing

2,089 posts

206 months

Wednesday 2nd December 2009
quotequote all
philpalmer said:
Thanks for the replies.
its a 1.7 sdi engine.

As its for my daughter I want a car thats going to be reasonably reliable as we live in the sticks.
I should find out later today the estimate for repair.
Which if you have any sense at all you will ignore. People who know nothing about cars, which I'm figuring includes you, seem to think that garages are the fount of all knowledge about fixing engines. They aren't! Most mechanics can barely replace external engine parts at random and usually to no good effect, have almost zero knowledge of how an engine actually works internally, the basics of the four stroke cycle, what finishes and tolerances are desirable on machined components, how to clean components properly even if they had the equipment which they don't, how to disassemble and reassemble without damaging most of the parts they encounter.

As a top race engine builder of 30 years standing I wouldn't trust the average garage mechanic to diagnose his way out of a paper bag or change a set of spark plugs. All you're going to do is piss away a lot more money on top of what you've already spent for "repairs" which are probably nothing to do with any real or imagined fault. The car's not worth spending any money on and certainly not an engine rebuild which will cost more than you paid for it in the first place and will probably ensure it'll never run properly again because they'll break most of what they touch while doing it.

Stick an AA or RAC recovery on it in case it does break down which will cost bugger all and leave it alone or get someone competent to look at it. In future don't buy cars off Ebay which you can't test drive first. Pay a few quid extra from a garage for something with a warranty if you don't have the knowledge to evaluate one properly.

If as you say you "need" something reliable then how is it any solution to buy an old and untried banger off Ebay for pennies? That's not a solution, it's a lottery. Why do you think people put cars on Ebay in the first place instead of the local paper where someone will want a test drive?

Anyway, whatever you do decide don't post it on here because it'll undoubtedly be very bad for my blood pressure if I'm foolish enough to read this thread again.

rev-erend

21,404 posts

283 months

Wednesday 2nd December 2009
quotequote all
I have to agree with most of what has been posted.

If the garage has said it's a bent conrod - it would be a very wild and probably bad diagnosis.

Do not trust that garage.

They will probable charge you for the labour to remove and replace rod and then charge you for what the actual problem is .. if they can find it at all.

As Puma says - a rod can only really be bent if you drive thru standing water and it's sucked into the engine - hydrolocking the engine. This is very unlikely indeed.

Buying any used car is a risk and it often pays to take a friend along who knows his stuff.

stevieturbo

17,229 posts

246 months

Wednesday 2nd December 2009
quotequote all
LOL biggrin



Dont let this lead the OP astray...

But I did have the surprise of stripping an engine a while back, that did have a bent conrod inside !!! How the hell it got that way absolutely baffles me, as it was being stripped for other reasons. And it wasnt even a small bend !

Although on the same note...also seen one in the past couple of weeks....a recently rebuilt engine too !! Bores half knackered, circlip missing from a piston, and the pin having gouged its way up the bore. Head gaskets leaking ( pressurising coolant and blowing it everywhere ), AND the crank ground 0.75mm and 0.50mm, which on Subarus, is a big no no.

How the engine ran seemingly fairly quiet was equally amazing !

fatjon

2,144 posts

212 months

Wednesday 2nd December 2009
quotequote all
I have built and worked on MANY engines and I could not diagnose a bent conrod without either a carefull measurement of the piston stroke and TDC height or a strip down. This diagnosis is probably way off the mark and you are about to get fleeced. Take it elsewhere.

eliot

11,365 posts

253 months

Wednesday 2nd December 2009
quotequote all
And if your daughter is a newly qualified driver, the chances are that the car will be trashed within a week anyway.

bertelli_1

2,235 posts

209 months

Wednesday 2nd December 2009
quotequote all
Pumaracing said:
Most mechanics can barely replace external engine parts at random and usually to no good effect, have almost zero knowledge of how an engine actually works internally,
A bit harsh I feel.

cptsideways

13,535 posts

251 months

Wednesday 2nd December 2009
quotequote all
IT's either:

Injectors needing cleaning, cheap & easy fix on those, ie take em out & clean the crud off the nozzles, or maybe an italian tune up might just fix it!!

Or dual mass flywheel falling apart as they do if its got one

Edited by cptsideways on Wednesday 2nd December 19:59

stevieturbo

17,229 posts

246 months

Wednesday 2nd December 2009
quotequote all
bertelli_1 said:
Pumaracing said:
Most mechanics can barely replace external engine parts at random and usually to no good effect, have almost zero knowledge of how an engine actually works internally,
A bit harsh I feel.
Sounds perfectly true to me.

eliot

11,365 posts

253 months

Wednesday 2nd December 2009
quotequote all
bertelli_1 said:
Pumaracing said:
Most mechanics can barely replace external engine parts at random and usually to no good effect, have almost zero knowledge of how an engine actually works internally,
A bit harsh I feel.
Lol..

Andoo

226 posts

172 months

Wednesday 2nd December 2009
quotequote all
Sorry, but I did laugh out loud at the the pic above with the bent conrod laugh

Very good biggrin

eliot

11,365 posts

253 months

Wednesday 2nd December 2009
quotequote all
Andoo said:
Sorry, but I did laugh out loud at the the pic above with the bent conrod laugh

Very good biggrin
its from Bertelli's site - which is rather aptly named conrod.co.uk

Pumaracing

2,089 posts

206 months

Thursday 3rd December 2009
quotequote all
bertelli_1 said:
Pumaracing said:
Most mechanics can barely replace external engine parts at random and usually to no good effect, have almost zero knowledge of how an engine actually works internally,
A bit harsh I feel.
If you'd seen what I've seen over 30 years of being around engines and what other people do to them you wouldn't think so.

I've watched a 7 year time served Ford and BMW main dealer mechanic trying to strip his own race engine down in my workshop. To get the cam pulley off a CVH head he put the cylinder head face down on the concrete floor, stood on it and started hitting the pulley with a lump hammer and a cold chisel he'd found in my tool cupboard. By the time I'd wondered what the hell all the noise was and wandered up to see what he was doing he'd destroyed the pulley plus the head gasket face. The pulley wasn't even on tight but hitting it on just one side with a chisel wasn't doing anything to remove it. I rescued what was left after his efforts, put the head on the bench, held the pulley evenly on both sides with a thumb on the cam nose and it slid straight off. It had to be binned and replaced and the head reskimmed of course. This guy worked on £50k BMWs but hadn't a clue how to treat engine parts without actually destroying them in the process.

It's pretty rare that garage mechanics actually work on engines these days. They service them, they do suspension bits and clutches and exhausts and swap ancilliaries but to strip an engine or understand how engines really work is unusual. Most garages have no tools for internal engine work, no machinery for skimming or pressing off pistons. All that gets farmed out. Most don't even have a cleaning tank or any comprehension of just how spotless an engine needs to be inside before it goes back together.

Nowadays most mechanics plug in a diagnostic machine and if that doesn't know what's wrong they're screwed. 40 or 50 years ago it was very different. Engines got rebuilt more often and most mechanics could do that well enough.

If you want your engine screwed get a garage to rebuild it. Far safer to just fit a complete known runner from a scrap car that no one's buggered about with.

A couple of other tales.

A local garage to me knew I always had plenty of CVH bits knocking around. They used to pop round for valve collets every now and then. I asked why. Turned out that when they used the Sykes Pickavant tool to remove the valve springs in situ so you could change knackered stem seals they never remembered to block the oil drain holes and consequently lost a couple of collets down the sump most times. I always wondered how much havoc those wreaked on the crank and rods but as long as the car ran long enough for them to avoid a comeback it was apparently never their problem.

I remember another place doing a blown head gasket on one bank of a Rover V8. The guy couldn't be arsed to remove all the manifolds and take the head right off and clean everything up and check it all properly or see if it needed skimming. With the studs out he managed to raise the head far enough off the block to slide the old gasket out and slide a new one in. I wonder how many bits of old gasket were stuck under the new gasket and how long that ran before it blew again.

Then there was Lord something or other with a collection of cars at his stately home who took his prized Lancia Gamma in for the cambelts to be changed. After that there was a tapping noise which turned rapidly into a rattling noise which turned into an absence of forward motion. Wisely he took it to a Lancia specialist who removed the engine and brought it to me unstripped for an expert diagnosis as the garage was denying liability. The flywheel on it had marks at TDC for cambelt changes plus marks at I think it was 30 degrees BTDC for ignition timing. The garage had set the cambelt timing using the ignition timing marks leading to all the inlet valves hitting the pistons. Every inlet valve was bent plus one rocker had snapped under the strain which had finally stopped it running. They paid up pretty quickly after seeing the report and I got the rebuild out of it at least.

Then there was the garage who rebuilt one of my race engines when the owner sold the car and the new owner didn't know where to take it back to for a proper freshen up. It had been a top runner when I'd built it but on the same dyno it was down 10 bhp after their efforts and finally the block split. I got it back to see what had happened. They'd honed the bores with some sort of hand tool but without moving it up and down as it rotated. The bores were just full of deep horizontal ridges that the piston rings were bouncing over. The heat and friction finally split the block open. With the head off and just the crank and pistons in it it still took over 30 ft lbs to turn the crank over.

I could go on but you get the gist.