Valve stem seals on VR6 -cost to fix and damage?

[Reverend Frog 10]

Having done a few searches on here I am pretty sure that my valve stem seals are nadgered. I’ve got a 2.9 VR6 with 97,000 miles on it. After it’s been allowed to overrun (engine braking) downhill and when I try to pull away afterwards, it bogs down monetarily and produces a puff of smelly blue smoke from the exhaust.

So I have two questions:

• How much, typically, would I expect to shell out for a top-half rebuild to rectify this? I have noisy tappets so would consider getting these looked at while it’s in for the work. (The previous owner claimed it had had a top-end rebuild in recent times, but I can’t remember why it needed it).
  
• Will I ruin the car by continuing to drive it until I get this remedied, or shall I just keep the oil topped up and avoid hills ?
  

 

Cheers

[subcool 0]

Sounds like worn pistons had the same problem myself and it wasn't the head!!

[Reverend Frog 10]

Sounds like worn pistons had the same problem myself and it wasn't the head!!

 

worrying, but thanks! How did you get it fixed?

[g0ldf1ng3r 15]

hello reverend

 

the first of your questions is very tough to answer but from personal experience it can turn out costly. at a guess maybe around the £1k to £1.5k depending on what is exactly done (but be prepared for much more! my budget went right out the window & into the ether lol)

 

I would check out your cars history for the rebuild info as if it has already had a top end rebuild they should have replaced the valve stem seals - which can cause your blue smoke

 

do you get any blue smoke on the first start of the day after leaving over night? reason I ask is that is a classic sign of valve stem seals on their way out - as the oil seeps past them over night & into the combustion chambers, thus resulting in a blue smoking on first start up that can then go away whilst it is running.

 

I had a top end rebuild along with some subtle mods a while ago, take a look at my build thread for an idea of what I replaced & what ailing components then also needed replacing due to them being weak links in the chain http://the-corrado.net/showthread.php?44751-g0ldf1ng3r-s-VR-amp-1-8-16V-headlight-woe-s/page2

 

as for the 2nd question - I wouldn't imagine it would do much if any harm to drive as it is. it may have a long term detrimental effect on the CAT but like you say just make sure you keep the oil topped up & it should be ok

 

by all means ask any questions you may have :)

 

hope that helps

[g0ldf1ng3r 15]

Sounds like worn pistons had the same problem myself and it wasn't the head!!

 

potential OUCH!

[subcool 0]

worrying, but thanks! How did you get it fixed?

Full rebuilt new big valve head cost around £3k plus by tsr performance in Somerset!

[Reverend Frog 10]

 

do you get any blue smoke on the first start of the day after leaving over night? reason I ask is that is a classic sign of valve stem seals on their way out - as the oil seeps past them over night & into the combustion chambers, thus resulting in a blue smoking on first start up that can then go away whilst it is running.

 

I don't believe so - I get condensation from the exhaust on first start-up, but I'm pretty sure it's not oil smoke.

 

If it wasn't for having to negotiate hills i wouldn't even know there was a problem with the car at all.

 

I suppose the main issue here is - how do you find out what it is without taking the engine apart? which is going to cost you regardless

[subcool 0]

If it's using a litre of oil every 500 miles and smoking on the over run then it's probably fooked like mine was!

[g0ldf1ng3r 15]

I don't believe so - I get condensation from the exhaust on first start-up, but I'm pretty sure it's not oil smoke.

 

If it wasn't for having to negotiate hills i wouldn't even know there was a problem with the car at all.

 

I suppose the main issue here is - how do you find out what it is without taking the engine apart? which is going to cost you regardless

 

I had the condensation issue too before my head work & before I got my longlife SS exhaust - it was the old CAT holding moisture. IIRC if you rub the smoke between your fingers you can feel if it is oily or not

 

how much oil are you using? the VR really should use much at all. I know mine normally uses maybe between a 1/4 to 1/2 a litre over 10,000 miles. IE only requires a very small top up on a couple of occasions between oil changes.

 

as you mention in your last sentence it is very difficult to pinpoint a suspect, if any, without taking it all apart.

 

has your had the chains & top & bottom tensioners done? if not you could have the head inspected whilst the rocker cover etc is off

 

I wonder if a compression test would help point you in the right direction. IE would it show lower compression on a chamber if say the piston or its rings or the chamber itself were worn? I would imagine so. that potentially could help you identify if it is top end of bottom end

 

either way, & whatever you do, I would advise trying to allow for at least double whatever the intended budget may be to allow for the replacement of other ailing parts which become weak links

[Kevin Bacon 5]

Sounds like worn pistons had the same problem myself and it wasn't the head!!

 

+1

 

I had the head done first, thinking the smoke was caused by worn guides/seals, but the increased vacuum made the smoke worse! It was the classic ovalising of cylinders 1 & 6 but switching to Silkolene 10W50 certainly reduced the smoking considerably.

 

If plugs 1 & 6 are caked in a white crusty substance, or are wet, it's definitely bores.

[Gti_Jamo 10]

If it's only on 97k it would be unlikely to be a bore issue but yeah check the plugs, especially the two outer cylinders 1 and 6. But it is not a definative test. Plus cylinder wear is likely to smoke badly when up the top of the rev range. The classic 'smoking after engine breaking down hill' tells me that it is stem seal related, particularly worn valve guides causing the seals to fail. Overun / closed throttle creates a vacuum that sucks the oil down past the seals then spits it all out the back in one go in a lump of blue smoke. Of course bad rings and bore wear can do this but they'll usually be accomplished with other symptoms like burning under load and excessive crank case pressure. Compression and leak testing may be worthwhile if there is doubt before stripping.