Jump to content
graham1971

Piston rings

Recommended Posts

I took my 94 VR6 to the local "German Specialists" thinking I needed the stem seals and valve guides replacing, they did a pressure leak test and informed me that they believe it to be the piston rings at fault and that this will require a full engine rebuild at a cost of around £2700 as long as they don't find anything else wrong while they're in there! This price does include renewal of all the usual engine parts, bearings, chains, gaskets and seals etc.

I would obviously love to get the work done if I was incredibly wealthy, however, I'm not!

Does the work involved justify the expenditure and is there any better (cheaper) way of getting it done that will provide the same result?

Share this post


Link to post
Share on other sites

always worth getting a 2nd opinion

 

how far are you from Stealth?

 

initial cost sounds about right but be prepared for it to climb, & potentially very quickly

 

i had a head rebuild at stealth & ended up chasing ailing parts round once new ones were installed, resulting in a cost over what you have been quoted

 

unfortunately you cant tell what might start failing or what else might need renewing until you make a start

 

personally, & i know others will differ on view, but i would discount an R32 swap (which could potentially work out cheaper) as it really removes the heart & soul of the VR - which is the 12 valve engine

Share this post


Link to post
Share on other sites

I'm in Swansea, it sounds like a mammoth task but if possible I would prefer to keep everything as original as possible so I'd rather stick with a VR6 than change to a different engine, although I did always love the sound of a large V8........

 

Sent from my Pixel using Tapatalk

Share this post


Link to post
Share on other sites

Presumably the car is using oil?

 

How much oil per 1000 miles?

 

Is it causing misfires due to fowling the plugs?

Share this post


Link to post
Share on other sites

The spark plugs were very sooty, cylinder 6 plug was sooty and oily, I've not kept track of how much but it was using regular oil with no sign of leakage. Only seems to smoke on startup. I'm starting to think a reconditioned engine may be my best bet but can't seem to find anyone who stocks them anymore. Anyone know of a reputable supplier?

 

Sent from my Pixel using Tapatalk

Share this post


Link to post
Share on other sites

Misfiring under what conditions? They all coke up and misfire a bit if they do a ton of short journeys.

 

 

A Corrado is for life, not just for the MOT.

Share this post


Link to post
Share on other sites

have you been doing a lot of short runs? Clean up the plugs and then take it for a good drive. Then take them out and have a look. It will be an easier diagnosis then

Share this post


Link to post
Share on other sites

The leak down test apparently showed that it is the piston rings, I'm not really worried that the diagnosis is wrong, more about how to put it right, for a more reasonable cost!!

Share this post


Link to post
Share on other sites

Leak could also be a burnt out valve, that would also cause a misfire, the VR engine isn't hugely complex.. have you thought about DIY?

Share this post


Link to post
Share on other sites

I've done quite a lot of DIY on the Corrado but engine wise I've never been brave enough to get inside, just plugs, leads, coil packs etc.

 

Sent from my Pixel using Tapatalk

Share this post


Link to post
Share on other sites

These are old cars.. I think I'd need some pretty bad symptoms to make me want to spend best part of three grand on an engine rebuild, personally. I would not be surprised if most VRs showed some issues if you look close enough.

 

 

A Corrado is for life, not just for the MOT.

Share this post


Link to post
Share on other sites

What oil are you using? It might be worth upping the grade and if you are not already, using fully synthetic. It does make a difference!

 

As for engine rebuild, I did mine when I first got it and think I worked out at about 1k in parts. That was chains, guides, head rebuild etc

 

Sent from my SM-G930F using Tapatalk

Share this post


Link to post
Share on other sites

Last time I used Shell Helix fully synthetic 10 w 40. I've now put it in with a company in Cardiff for a rebuild, still expensive but not as much as I was quoted locally. It's not a company I've used before but a specialist engineering shop in Swansea recommended them so fingers crossed!

Anybody on here had the engine reconditioned before? What should I look out for when I get her back?

Share this post


Link to post
Share on other sites

It's my understanding from conversations with Stealth prior to my last engine rebuild, and from various other sources, that simply replacing the rings is unlikely to be all that needs doing. Yes it's possible that rings are no longer sealing properly but there's other factors to take into consideration with the cylinder bores such as the bores becoming slightly ovalised (which can be corrected with machining assuming they're not TOO worn) or tapered.

 

A cheaper option could just be to live with it.. what exactly are the symptoms / problems? Alternatively you could take a punt on a low mileage 2.8 VR6 from a breaker and have that installed.

Share this post


Link to post
Share on other sites

agree with what Jim has said - plus the block should be re-honed AFAIK

 

also - i thought my VR was seeping oil past valve stems due to smoke on start up

 

but said smoke was there after head rebuild

 

Vince did some major testing & found that it was my OE cat producing the smoke, which wasnt smoke but water vapour as the cat was holding excess moisture

 

once the cat was hot the smoke went away & after having my Longlife SS exhaust with hi flow cat fitted ive not had any start up smoke since - FYI the exhaust was £400 which is massively cheaper than a bottom end rebuild

 

graham, is it still running the original (or old) OE cat & exhaust?

 

though i must add the caviat that my VR passed the leak down test vince did

Share this post


Link to post
Share on other sites

The price I was quoted (£2700) was for a full rebuild, not just the piston rings. They were going to replace all of the bearings, seals, gaskets and valve guides etc, in both the bottom block and the head ... but, they did warn me that price did not include any extra machining that may have been required such as any re bore and larger pistons.

 

I do have an aftermarket stainless steel exhaust from longlife on the car but the cat hasn't been replaced to my knowledge.

 

My mechanical knowledge is limited as I've said but there was a substantial cloud of white smoke on startup and under load, the spark plug on cylinder 6 was heavily coked and oily and it failed the leak down test.

 

I've had a much lower price from the place the Corrado has now gone to for the rebuild, they have good reviews on Google and they sounded quite knowledgeable. It sounds like they're doing exactly the same job that the "VW specialist" quoted but for around £1100 less, still a lot of money but if it's done properly my understanding is that it should run like a brand new engine.

 

I could have made a massive mistake if this goes wrong but I was worried about buying a 2nd hand engine with no history as it may be worse than mine! I did try to live with it but the oil leaking through was causing a lot of misfiring and I was getting too frightened to drive her far which is kind of against the point of owning her!

 

I wish I had the knowledge, time and room to have a go at this myself but I don't, I hope to keep the car forever so my only option was to get it done one way or another. Fingers crossed!!!

Share this post


Link to post
Share on other sites
The price I was quoted (£2700) was for a full rebuild, not just the piston rings. They were going to replace all of the bearings, seals, gaskets and valve guides etc, in both the bottom block and the head ... but, they did warn me that price did not include any extra machining that may have been required such as any re bore and larger pistons.

 

I do have an aftermarket stainless steel exhaust from longlife on the car but the cat hasn't been replaced to my knowledge.

 

My mechanical knowledge is limited as I've said but there was a substantial cloud of white smoke on startup and under load, the spark plug on cylinder 6 was heavily coked and oily and it failed the leak down test.

 

I've had a much lower price from the place the Corrado has now gone to for the rebuild, they have good reviews on Google and they sounded quite knowledgeable. It sounds like they're doing exactly the same job that the "VW specialist" quoted but for around £1100 less, still a lot of money but if it's done properly my understanding is that it should run like a brand new engine.

 

I could have made a massive mistake if this goes wrong but I was worried about buying a 2nd hand engine with no history as it may be worse than mine! I did try to live with it but the oil leaking through was causing a lot of misfiring and I was getting too frightened to drive her far which is kind of against the point of owning her!

 

I wish I had the knowledge, time and room to have a go at this myself but I don't, I hope to keep the car forever so my only option was to get it done one way or another. Fingers crossed!!!

 

sounds like you have made the best decision you are able to at the time, which is all anyone can do for the best

 

with the array of symptoms im sure that decision is a good one & fingers crossed for you that the place it is at do a good job.

 

the majority of the price would be for the labour so as long as the place it is at are competent your saving could simply be due to them having a lower hourly rate than the specialist & work quality should be the similar

 

i also agree with the 2nd hand engine bit, you know the history of yours & with the ailments fixed it remains original & a matching number car

 

keep us posted :)

Share this post


Link to post
Share on other sites

I just picked up my Corrado from SVS in Cardiff where the work has been done to recondition the engine. I have to say that the early indications are great, she sounds fantastic again, no smoke, engine feels right and powerful although I'm not allowed to push her too hard for the first month or 500miles.

One completely unexpected benefit was that on the 50 mile drive home she averaged 37mpg according to the MFA!!!!!

Looks so far like a lot of money well spent, I'll update the thread as things develop but I'm very happy so far.

Giving her a good clean and polish now as a treat!

 

Sent from my Pixel using Tapatalk

Share this post


Link to post
Share on other sites

great news graham - really pleased it is working out for you

 

& yes be careful with your rev range on that freshly rebuilt bottom end

 

out of interest, did they re-hone the block too?

 

37 on the mfa is good & about average if you drive the VR lazily - it always makes me laugh the way new car manf's go on about 45mpg etc when we can get very close to that with our 20 year old motors ;)

Share this post


Link to post
Share on other sites

I did a complete engine rebuild on my VR6 about 8 years ago. The engine had apprently dont 85k odd (its in a mk2) but wasnt running great and i had smoke going up the quarter mile which i thought was valve stem seals

 

When it was taken apart. OMG it was terrible, it looked like no one had ever put any anti freeze in as it was rusty as hell, the cams were hugely out in the head, and well the pistons, you could rock them in the bores and there was horrible piston slack.

 

So it was honed out to a 2.9 and 2.9 pistons put in, new shells etc etc, head rebuild. Basically everything rebuild. It cost me at full retail from VW £1600 on parts. The pistons were £600 alone. I was lucky that with the help of a friend i did it myself so there was no labour costs. i personally have had the car 12 years so for me i have no plans to ever sell so worth every penny IMO.

Share this post


Link to post
Share on other sites

Lol, it may well be at least partially my right foots fault but I can't remember the MPG of mine ever getting above 30 before!

Yes the block has also been done, the price sounds high when I say it to myself out loud but I know the parts alone aren't cheap and it is a lot of work, I can't help feeling that if this all goes to plan It's actually a bit of a ...... Bargain?

 

Sent from my Pixel using Tapatalk

Share this post


Link to post
Share on other sites

I've seen 37mpg on mine, with 130k miles on the clock. You do have to drive very, very carefully though..

 

Forget 45mpg as a target though, the new 1.2 TSI polos will bang in 65 - 70 mpg in the same circumstances.

 

 

A Corrado is for life, not just for the MOT.

Share this post


Link to post
Share on other sites
Lol, it may well be at least partially my right foots fault but I can't remember the MPG of mine ever getting above 30 before!

Yes the block has also been done, the price sounds high when I say it to myself out loud but I know the parts alone aren't cheap and it is a lot of work, I can't help feeling that if this all goes to plan It's actually a bit of a ...... Bargain?

 

£1600 is VERY cheap for a full VR6 rebuild, if indeed that's what it was. Fingers crossed your new found oomph, frugality and reduced smoke remains that way for years to come!

Share this post


Link to post
Share on other sites

It actually came to £1800 overall but I'm more than happy at the minute kev, I suppose the real test will come after running in when I bury my foot into the carpet and pray!

I wish I could have had a go myself but I'm enthusiastic and semi skilled which is a recipe for disaster!

 

Sent from my Pixel using Tapatalk

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...