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[Peterskinn]

Well..........

It's getting slightly better.

The cam belt was a red herring - checked again having re-read the instructions and all was well. I think the slackness I saw was just the way the engine had settled when it stopped. Certainly, when running, the pointer on the tensioner is spot-on.

Have today fitted the GM Cam Sensor (£57!) and the engine starts fine and GB operation is OK (Kick-down, sport mode,  the lot!)

As I drove off I'm thinking - great stuff - HOWEVER very soon I got a misfire again.

I'm thinking that I have eliminated the Cam Sensor so I'm wondering whether the coil pack breaks down as the engine gets hot?? Is that feasible?

Certainly a "Misfire on No 4" was one of the fault codes my friendly garage found. (along with many others)

As a basic check I removed all the spark plugs. No 3 was v dirty - the other three looked fine and very clean. I swapped the No 3  pro-tem and again - when cool - the engine ran fine. Within 1/2 mile the misfire returns!!

Any ideas?

Otherwise a very nice car is edging nearer the scrapheap..........

[SIR Philbutt]

Coil pack can be sensitive to temp, also, the rubber "boots" can break down and cause the spark to "leak" away. Check for cracking or bits missing, these can be replaced and reasonably cheap from GM

£57 seems cheap for a cam sensor from a GM stealer, well done

Reading your earlier post you mentioned coolant loss. Is this still occurring? as this along with a missfire can be a sign of the head gasket failing. Under certain circumstances HG failing can show itself as the engine warms and very quickly gets worse. This happened to me when I ignored coolant loss and misfire once.

[Peterskinn]

As I write I'm awaiting the arrival of the coil pack.

I suppose the only thing after that is the crankshaft sensor

......and then - yes indeed the head gasket!

I have a feeling this one will run and run......

I feel I might be suffering from putting heavy use onto a car which has clearly not done a lot of motorway miles (90K in 12 years??)

Ah well.

[Peterskinn]

Looks like it's the head gasket.  Losing water very quickly.

I am now suspecting that the previous work solved the gearbox problem but that the returning misfire was the head gasket. Personally I've never known a HG go with a bang like that - usually a very slow-burn experience?

Or am I just remembering life through rose tinted specs?

I'll keep you posted - Aaaaaaaaargh!

[Peterskinn]

Oh Cor Blimey - this gets worse............

Garage have been doing the work (as a cash "Inbetweener") and have called today to say that, having removed and skimmed the head they have now re-assembled

Now they come to timing it all up and have found that the engine won't turn - I assume it stops just before TDC.

Is it possible to have removed too much material from the head thus bringing the head down so low that the pistons foul???

Or am I seeing the worst and it's just a valve in the wrong position. I guess basically he question is - how much room is there??

As I've said before - Aaaaaaaargh!!

[SIR Philbutt]

Sounds like cam belt aligned wrong to me. Pistons will hit valves if this is so, and their problem to resolve as ok before

Would have to skim a lot off head to cause this, and of course their fault not yours, info on skim limits generally available to people that do this type of work

[Peterskinn]

Thanks - I'll pass that on........

Peter

[Andy A]

Peter, Check to see if they have the crank pulley mark aligned properly at the bottom like this

https://www.flickr.com/photos/53447058@N05/14079701179/in/datetaken/

and not with the pin at the 2 o'clock position. You can just see the pin to the right of the cam/timing belt.

https://www.flickr.com/photos/53447058@N05/14140445632/in/datetaken/

Hope this helps.

[Peterskinn]

Well - I hesitate to write this but........

I've now had the car back from the garage and driven nearly 400+ miles. So far so good. The problem with the engine turned out to be a bolt that had fallen through the sparkplug hole!!

Lumpy tickover now - but that's the least of my worries after this lot!

Will continue to drive carefully and see how it all progresses!!

[EMD]

Well - I hesitate to write this but........

I've now had the car back from the garage and driven nearly 400+ miles. So far so good. The problem with the engine turned out to be a bolt that had fallen through the sparkplug hole!!

Lumpy tickover now - but that's the least of my worries after this lot!

Will continue to drive carefully and see how it all progresses!!

 

[Peterskinn]

My thoughts exactly!!

I guess we were lucky that it prevented the engine turning at the set up stage. Had it been elsewhere and not been spotted - that would have been the end of the engine!

[SIR Philbutt]

Lumpy tickover is more than likely a vac pipe/EGR problem seeing as the head has been off.

Lightly spray brake cleaner around the inlet/brake servo area and the rear of the head. If tickover restores that will confirm it.

Then process of elimination will find the leak

[Peterskinn]

I have wondered about starting a new thread - but here goes anyway.

I've had the car back now for couple of weeks during which time I've done about 600 miles. In an effort to cure the lumpy tickover I followed all the advice and did the throttle body strip/clean and whilst I was under the bonnet cleaned the oil breather, EGR valve and the MAF. Other than the breather pipe all was dirty but nothing appeared to be blocked

Started up and all worked OK even did a test drive and it certainly performed better.

Came to get in it today, started up  and NOTHING. It would start and hold a - sometimes erratic - tickover - but there absolutely NO response to throttle pedal input.

Checked the obvious things like the plug connectors etc - all seemed OK. Will have another go later - But (here we go again) anybody got any ideas?? 

[EMD]

Any codes ? Maybe coil pack breaking down 

[flyer 0712]

Could it be the throttle sensor on the pedal ?