Gathering Cav Engine Fail Assistance

[crazycruzer]

Hello there,

Well as I'm sure all of you who went to the gathering this year know the cavalier engine decided to let go fantastically on track resulting in an impressive james bond style smoke screen which continued as I limped round the track!

I called the AA out ( other recovery companies are available) and they diagnosed it as terminal and I got a lift home on the back of a recovery truck.

Anyway yesterday I started it up to move it an I was still running on 3 clyinders and puffing the blue smoke. but...... all of a sudden the smoke stopped and I had 4 cylinders again. took it for a blast down the road and it was holding back but no smoke.

Now the initial consusus from all at RRG was that I had dropped a piston ring which made sence, however since it has now gone back to working on 4 cylinders and without the smoke I am wondering if it could be somthing like a sticky valve?

I have ordered a compression tester to try and isolate the cylinder, but please put up your thaughts coz this is not somthing I have personally come across before and its confusing the hell out of me!

The engine is a vauxhall C20XE also know as the redtop, its a 1998cc twin cam.

Thanks in advance fellow Retroriders


DSC_3069 by Nick Shaw, on Flickr

Pic of the lesser smokie section for your amusement

[jrevillug]

I saw it happen, and was gutted for you - I hope it easily fixed.

At the time it looked like clouds of steam from a blown head gasket, but thinking back it hung around, and steam dissipates really quickly. It certainly wasn't black enough to be a fuelling issue, but it didn't really look blue enough to be oil.

Are any of the fluids down from their normal level? If so, which ones? Do check the brake fluid - if the master cylinder/servo dies then brake fluid can find its way into the inlet, and I understand that it burns white. If the take-off is right at one end of the manifold then it might have gone into only one cylinder.

Another thought is that the crankcase breather might have chucked a whole load of oil into the inlet manifold in one go - again that could cause losing a cylinder and loads of smoke.

Unlikely to be a sticky valve, TBH - that wouldn't cause oil to find it's way into the cylinders.

Quick check - take the spark plugs out, noting which cylinder each one came from. They should all have a small amount of deposit on them, and that deposit should be light beige/tan in colour. Dry but black = running rich. Wet, oily and black = burning oil. Super clean = head gasket (steam cleaned).

I suspect that one plug will be black and oily, and another one or two a bit dirtier thanmight be expected.

[claymore]

Your not telling people the whole story are you Rich? ...lol, could the oil level have anything to do with it?

too much oil might cause this:
\/ \/ \/ \/ \/ \/ \/ \/

"Another thought is that the crankcase breather might have chucked a whole load of oil into the inlet manifold in one go - again that could cause losing a cylinder and loads of smoke"

[bortaf]

As above a sticky valve wouldn't make it smoke but it could cause a miss, where as oil in the cylinder will do both, have you checked your not out of oil and thats why it stopped smoking ? or it could have been a stuck pressure relief valve on the oil pump failing to open at high pressure and sticking ?

[crazycruzer]

The oil level was a tad high becuase i had to put in an adative to try and temporary fix a weeping crank seal that i didnt know about ( i thaught it was the sump gasket which i changed on the thurs. I think my best plan of action is to do a compression test to see if there is any losses there and do another oil change see if the fluid levels also have any issues.

Thanks for your help guys

[Steve]

Have you done the rocker cover mod mate?
Xe's in their natural habitat do seem to have oil surge issues and the mod is meant to help get rid of the problem

If its running right again and the smoke has cleared then id be tempted to run it around for awhile and see if you can replicate the problem again under similar conditions(obviously....on a private track )

Steve

[bortaf]

what arethey like on the crank breather front? could be the valve in that sticking (if they have one?)

[crazycruzer]

Steve, good call, I havnt done the rocker cover mod. Il attempt to replicate similar conditions having reduced the amount of oil in the bad boy and see what happens

cheers Rich

[murran]

i suspect if the oil level was too high coupled with the oil surge the standing oil in the sump might have got whipped up by the crank.... and into the breather system.

[Deleted]

I'd have to agree recon oil entered the head breather straight into the engine and oiled up the spark plug causing the misfire, probably due to giving it a lot of beans

[bmboy]

I'll be interested to see how this turns out. It really did look like a sad end, but maybe its an easy fix eh?

[mk14dr]

I was wondering what issues were appertaining to the Cav.
We were stood halfway up the hill and there was a collective sharp intake of breath when it happened. It was an impressive smokescreen you created though
If this turns out to be a simple fix I'll be well chuffed for you.

I have to say, I had assumed you were running an LET and that the turbo had let go.

[HARDCORE]

Aug 30, 2011 15:23:28 GMT mk14dr said:

I have to say, I had assumed you were running an LET and that the turbo had let go.

That's exactly what I said to my friends when it happend..

[crazycruzer]

Aug 30, 2011 16:30:08 GMT HARDCORE said:

Aug 30, 2011 15:23:28 GMT mk14dr said:

I have to say, I had assumed you were running an LET and that the turbo had let go.

That's exactly what I said to my friends when it happend..

yep, no turbo here, just a well tuned xe lol!! still havnt had chance to look at it yet, its still under dust covers atm! hopefully il get chance to have a look soon. however the potential rebuild has enspired me to look a little left field, and i think I'm going to try and run it next year with a merc compressor on for sh1ts and giggles!! if nothing more it should go very well and make an awsome sound :-)

[mk14dr]

Supercharger would be fun, you know what'd be fun-er though...? Saab 2.3t motor and wind the boost up.....

[brettsri]

Aug 29, 2011 13:41:28 GMT @moore said:

I'd have to agree recon oil entered the head breather straight into the engine and oiled up the spark plug causing the misfire, probably due to giving it a lot of beans

I bet this too. Common as hell on XE engines, oil comes down the breather, into the inlet and hey presto - mental smoke screen. If your oil was overfilled then thats why its so bad.

I'm really suprised that its taken this long to work out, Redtops are really well known for it - theres a mod you can do to one of the breathers on the underside of the cam cover, its called the breather mod normally, loads of stuff on the web about it.

MIG probably has a how too.

[crazycruzer]

yeh indeed, tbh tho ive never had the problem before and i have been on a few tracks in it, i think the addative to temp fix the leak may have pushed it over the limit.

Nice idea with the saab lol, il have to look into that

[nofrills]

my fiat 2.0 20v does this every now and again, its the breather valve that has gone, its a £5 quid fix for mine, hope yours is the same buddy

[Speedman]

I was stood by the top hairpin when it happened. You were coming up the straight towards the hairpin and then it puffed. I can't see it on any of the photos, but after you had passed there was a very clear thin black oil line up the centre of the track, the marshalls weren't fussed with it as it soon got dusted over with the passing cars.

[Deleted]

I'm also gonna go with oil surge! I had my Fiesta do exactly the same with the 1600 in, giving it beans on a hard turn, i thought i'd killed the engine! Then it cleared up, thats when i realised, the hard turn combined with hard on the throttle sucked the oil out the sump lol!