Vauxhall Turbo Problems

[steve in stockport]

Last week I had the 2B on a rolling road, mainly to sort out the fuelling, but to find out the power output too.

The bottom end fuelling was way out and during the course of altering this the engine did do a bit of pinking on a couple of occasions.

Later in the session the exhaust started to smoke quite heavily at one stage which it hadn't done before, then it blew oil and fumes from the dipstick and possibly under the cam cover.

Checked inside the inlet and all dry and clean so not drawing oil from the turbo.Then we decided that the engine breathers were all wrong with nowhere for crankcase pressure to go, forcing oil into the cylinders causing the exhaust smoke as well as out of the dipstick and under the cam cover.

So a 20mm breather was made from the cam cover to atmosphere and and the engine run up again and all seemed ok, until when taking it up through the revs again it started chucking more smoke out of the exhaust.

Back down to tick over and it was running on 3 cylinders and smoking heavily.

General concensus was somethings properly broken - rings, piston or cylinder - and not to run the engine anymore and recover the car home.

I've removed the inlet manifold in preperation for pulling the engine out at the weekend to find a lot of oil sat on the back of the inlet valves on cylinders 2,3 and 4. As well as this there seems to be what looks like melted plastic on the valve stems. The inlet tract from turbo to throttle body is bone dry and spotlessly clean, so I can only assume the oil is coming past the valve stem seals which might have somehow melted.

 

Does this sound plausible?

 

Next step is to carry out a compression test to confirm or eliminate piston/ring damage, it's the oil on the valves and melted plasticy substance that's throwing me.

[Bob Tucker]

Hi Steve,

That's a bu***r

Failed stem seals could account for some symptoms.....but not all.

where on the valves is the plastic? Is it in the inlet tract, or inside the spring(s)?

I cant see the stem seals going down the valve guide...

What do the plugs look like? We use a jewellers loup (magnifying glass) on the Vette plugs.....

at that magnification it can be scary,,,,even on healthy plugs....but any problems can be clearly seen.

Detonation leaves tiny aluminium dots on the electrode, without marking the pistons.

Something as simple as failed valve stem seals causing oiled up plugs could cause the misfire...

Also the +ve pressure in the inlet tract could pressurise the cam cover & then the crankcase

via the breather tube joining the 2.

BTW dunno if turbos act the same, but the Vette showed -ve inlet pressure up to 3.5 K, & only then showed +ve pressure

We anticipated +ve pressure all the time. - & + presures will show different symptoms.

Bit of a puzzle...best of luck with it

 

Did you suck in any small plastic cars?

 

Bob

[Grim]

Sorry to hear of your problems, keep us up to date and let me know if there's anything i can do!

[Guest chris brown]

Hell Steve that sounds bad but lets hope it is something simple as Andy says keep us informed.

[steve_wilson]

valve stem seals are quite a common issue on z20lets, might be part of the problem.

 

doesn't sound good though, hopefully its an easy fix though! let us know how you get on.

 

steve

[steve in stockport]

it's officially fubar!

I thought that there may have been a glimmer of hope when I found oil in the inlet manifold after the throttle body, but it was not to be.

Did a compression test this afternoon and the figures aren't pretty

Number 1 - 140psi

Number 2 - 180psi

Number 3 - 0psi

Number 4 - 90psi

 

I really don't think it's worth dropping a bit of oil down the plug hole to see if it'll bring the figures up.

So, no Newark for me this weekend, I'll be pulling the engine out, stripping it and getting it ready to go for a rebore/hone/rings/whatever else while I'm on holiday.

[Guest Tim Norman]

Sounded fun while it lasted!

Hope you get it sorted soon, have you tried asking on any of the Turbo forums?

[Tazzzzman1]

Sorry to hear that Steve.

Was looking a really nice install as well. Hopefully you have deep pockets and will be on the road to enjoy this cracking summer were having.......all 2 days of it

[Guest mower man]

That's abummer Steve hope you get a good rebuild ,never know it could be even quicker!!! mick

[Guest peter2b2002]

sounds like a hole in No,3 piston if it was pinking and now zero pressure

peter2b

[Longboarder]

In a kind world the weak running might just have cooked the exhaust valves to red hot and melted the stem seals. Then while the engine was stopped and cooling the goo on no3 &4 exhaust stuck 3 wide open and 4 just off its seat as it solidified and all you need is four new exhaust seals! Well you can dream. It could happen. Good luck.

 

Nigel

[Kerry]

Hi Steve, gutted to hear about engine.. Sounds like detonation which burns down the side of the piston, pretty much like what happend to my red top .. I

Your compression seems high on the good cylinders, what should it be?. I run thick head gasket which gives low compression, that allows me to run high boost without pinking. Let me know what you find. Cheers, Kerry

[Bob Tucker]

Sounds like a real B....

Just make sure you pinpoint the cause before the rebuild...

[steve in stockport]

engine is out, I'll have some sort of idea what's gone wrong later on today.

The comp figures are all over the place and as I don't know what they should be not sure which is good and which is bad apart from the obvious 0psi

[steve in stockport]

number 3 piston is definitely not right, obviously been some detonation going on which has managed to go unchecked and melt the piston crown and carry on down past the ring and out of the bottom of the piston.

Melted alloy stuck to the bore which may machine off with a minimal rebore and still use standard rings or maybe a 0.5mm overbore

 

 

 

I'll have all the pistons out tomorrow to check for more damage as the comp readings were all over the place