sick V8

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jvaughan

Original Poster:

6,025 posts

290 months

Tuesday 6th April 2004
quotequote all
Took the 400SE to Peninsula for a Per-LM service, and MOT, only to be informed the high oil consumption I have been experiencing is not normal. Peninsula are currently investigating

stainless_steve

6,034 posts

265 months

Tuesday 6th April 2004
quotequote all
sounds like a rebuild, but look on the bright side engine mods start making your list

Boosted LS1

21,198 posts

267 months

Tuesday 6th April 2004
quotequote all
Have you noticed any smoke? Maybe it's been leaking?

2 sheds

2,529 posts

291 months

Tuesday 6th April 2004
quotequote all
How much oil is being consumed ?
As boosted suggested, if its not smoking it must be "dripping" somewhere.
hope its something simple.
Tim

jvaughan

Original Poster:

6,025 posts

290 months

Wednesday 7th April 2004
quotequote all
2 sheds said:
How much oil is being consumed ?
As boosted suggested, if its not smoking it must be "dripping" somewhere.
hope its something simple.
Tim


The engine was new and did already have a list of "mods" done to it .. lightened flywheel, solid lifters, x-bolted, steel pushrods, Wild CAM, STage-3 heads... it has only done 1700 miles, and has burnt oil all its life. At first I put it down to running it in, but it's getting through about 3 pints per 100 miles or so (cruising at 80 - 100mph). There are no signs of oil leaks on the garage floor. (since new, I have put in almost 9 litres of oil in the engine)

Fingers are crossed its not terminal (although it is under warrenty)... watch this space .. updates as soon as I get a synopsis from Peninsula

HarryW

15,277 posts

276 months

Wednesday 7th April 2004
quotequote all
Did it consume much in the way of oil during the running in period , or is it a recent thing?

****.

Harry

>> Edited by HarryW on Wednesday 7th April 17:44

jvaughan

Original Poster:

6,025 posts

290 months

Thursday 8th April 2004
quotequote all
Early diagnosis shows good compression on all cylinders, wet test is also good (whatever that is).
No oilseals leaking, bearings or gaskets leaking, and no oil in the coolant.

Suspect possible piston ring failure... engine is off to V8Developments for further inspection, rectification next week.

HarryW

15,277 posts

276 months

Thursday 8th April 2004
quotequote all
If all compressions are OK then I'm not sure how a failed piston ring wouldn't show up.

not got a hole in the sump has it or if you've got a oil cooler its not got a hole in it

Seriously though if its burnig it, doesn't it show up as a very high HC reading on a gas analyser/ emmissions test.

Assuming V8D built it in the first place, I don't think they get many returned so just one of those things then

nel

4,797 posts

248 months

Thursday 8th April 2004
quotequote all
Agree with you - would have thought that a dodgy ring would show up as a cylinder down on the compression test. Trying to think where else it could go - haven't forgotten to fit stem seals on the tops of the valve guides have they?

Nel

greenv8s

30,475 posts

291 months

Thursday 8th April 2004
quotequote all
If the rings haven't bedded in properly they may not be sealing properly, so it would blow oil out the breather. The breather is normally plumbed into the inlet manifold so the oil gets burnt. I think its quite common for new engines to blow a little while they're being run in, but I couldn't say what constitutes 'a little'. My 4.6 didn't consume much oil while it was being run in.

jvaughan

Original Poster:

6,025 posts

290 months

Thursday 8th April 2004
quotequote all
Will wait and see what the diagnosis is next week ...

nel

4,797 posts

248 months

Friday 9th April 2004
quotequote all
greenv8s said:
If the rings haven't bedded in properly they may not be sealing properly, so it would blow oil out the breather. The breather is normally plumbed into the inlet manifold so the oil gets burnt. I think its quite common for new engines to blow a little while they're being run in, but I couldn't say what constitutes 'a little'. My 4.6 didn't consume much oil while it was being run in.



Oh yeah ! That might be the job - break the glaze on the cylinder bores for a nice scratchy, crosshatchy finish. Hadn't thought of that...

apache

39,731 posts

291 months

Friday 9th April 2004
quotequote all
After 1700 miles?

nel

4,797 posts

248 months

Friday 9th April 2004
quotequote all
Could be - if the surface finish of the cylinder bores is not right when the engine build takes place then the piston rings don't bed in. The final finish is normally acheived by honing to give a roughened, cross hatch effect that (I think) allows some oil retention in the valleys to lubricate the passage of the piston.

Anyway, remember when I were a lad an engine coming back with this problem and I was given the job of dropping out the pistons and "breaking up the glaze" with diagonal strokes of roughish wet and dry. Did the trick as I recall.

Nel

jvaughan

Original Poster:

6,025 posts

290 months

Friday 30th April 2004
quotequote all
OK Engine Update ... The guys at V8 Developments have I believe found the problem of excessive oil consumption and low power output.
Valve guides ... detatched and very very worn (1700 miles from new).
They are re-doing the heads, and the engine should be back with me within the next 2 weeks

>> Edited by jvaughan on Friday 30th April 19:47

stainless_steve

6,034 posts

265 months

Friday 30th April 2004
quotequote all
jvaughan said:
OK Engine Update ... The guys at V8 Developments have I believe found the problem of excessive oil consumption and low power output.
Valve guides ... detatched and very very worn (1700 miles from new).
They are re-doing the heads, and the engine should be back with me within the next 2 weeks

>> Edited by jvaughan on Friday 30th April 19:47

Glad it's getting sorted, but did you have the heads done by them before?

HarryW

15,277 posts

276 months

Friday 30th April 2004
quotequote all
Jason were they the Stage III ones from them . If so I hope they don't have too may failures, mine will be out of warrantee soon .

Harry

jvaughan

Original Poster:

6,025 posts

290 months

Saturday 1st May 2004
quotequote all
HarryW said:
Jason were they the Stage III ones from them . If so I hope they don't have too may failures, mine will be out of warrantee soon .

Harry


Yes, they were stage III heads. This problem though has been with me from the start (+- 50 miles), so no worries I guess about them suddenly going. Still, im sure the guys at V8 Dev would sort you "IF" they were to develop a fault, I have been assured it is a one off case.

all that will remain is for me to drive the car everyday to work for a month to run the engine in before Le Mans

2 sheds

2,529 posts

291 months

Saturday 1st May 2004
quotequote all
Good news Jason.
I can verify that this is very unusual with their heads.
Tim