[AndersonDic]

Hello again all.
I have a problem on the above-mentioned car.
When starting from cold i.e. if the car's not been used for 36-48 hours or so, the engine seems to only fire on 3 cylinders. It sounds really rough and goes...."Chug...chug...chug..."(!). After about 5-10 seconds, the problem clears and everthing is fine with engine running sweetly and no mis-firing at all. If the car is started on say, the next day after it has been previously used, she starts fine with no "chugs". However, if it's TWO days later or more, we get the above problem.
I have replaced the plugs with the correct NGK 7-11 jobs and replaced the DI cassette with a new one. All was fine until I had occasion to leave the car for a couple of days - then started her up...and...."chug...chug....etc"
There is no apparent leak from the head-gasket and no apparent coolant loss - I am baffled! Can anyone help?
Car is MY 97 Aero Manual (Black with Sand Beige Leather), totally standard with 69K.

 

[djtaylor]

It's the "no apparent leak from the head gasket" that interests me.

That's pretty much what my 2.0 did when it had a cracked head.

David.

 

[1989agoodvintage]

I'd agree with David, sounds suspiciously like a cracked head to me as well. Did they do a block test, i.e. check for exhaust gas traces in the coolant?

 

[AndersonDic]

Jason,

No block test done yet - I'm wondering whether to get the car in somewhere for them to do one. Tell me - should it be done under the "not started for 48 hrs" conditions?....or just tested "from warm"? Will this make any difference to the reading in the test?....Thanks for all the input, by the way!!

Richard

 

[ben hall]

It could still be the gasket and not a cracked head. Exhaust gas in the coolant could be either.

If the gasket is only just beginning to go, then when the engine is hot exhaust gas from the cylinder can be forced into the coolant, which overpressures the cooling system. When you stop the engine, coolant under pressure is forced back into the cylinder. Then, when you next come to start the engine it misfires until the small amount of water has been blown out of that cylinder.

After a run check your coolant expansion tank. If it's overpressured you'll see coolant bubbling into it from the small hose coming from the top of the radiator.

Now is definitely the time to get it checked out. If the gasket lets go big time when you're driving then you'll suddenly fill a cylinder with a lot of water.... which is incompressible.... and you don't want to go there.

 

[1989agoodvintage]

Originally posted by Alton Aero:
[qb]Tell me - should it be done under the "not started for 48 hrs" conditions?....or just tested "from warm"? Will this make any difference to the reading in the test?[/qb][/b]

Mine was tested after it had been driven the 12/13 miles to Erdington, so it doesn't matter as far as I know. I just hope you are luckier than I was!

 

[Paul D]

Sounds like a classic case of head gasket starting to leak water into one of the cyclinders. In my experience, it's usually cylinder 4 (on battery side of engine block).

The easiest/quickest test for leaking head gasket is check spark plugs. The plug on the leaking cylinder will normally have distinct white deposits on it, instead of the typical grey soot.

The effect is more pronounced after engine has reached higher temps. When engine off, the water jacket, which is under pressure, squeezes a little water into the cylinder, especially after the cylinder has cooled, and the pressure on the gasket has reduced. (Sorry BenH - just saw your similar comment)

If too much water gets into cylinder, you can get aqua-lock! This is where piston jams on compression stroke, due to compression area filling with water. Would need a serious leak to get this bad though!

Ballpark, aim for £300 inc, for non-franschised specialist doing head gasket replacement.

Hope this is of some help!

 

[AndersonDic]

I have to admit that, after close inspection, there IS a certain "whiteness" to the recently extracted spark-plugs. Having never changed any before, I was unaware of what they SHOULD look like..
Block test being done over the next couple of days...and at this stage, I would rather know for certain exactly what the problem is - once and for all, so I can rectify things. I was bargaining on keeping the car for at least the next 5 years or so!
If it IS gasket replacemet job, should I replace the original DI and keep the new one as spare..or just keep using the new one? Any thoughts?

Richard

 

[1989agoodvintage]

You shouldn't need to replace the DI providing the terminals on the new plugs are coated with dielectric grease. It's also wirth putting a dab of grease on the DI terminals at the same time, just don't go too mad.

 

[AndersonDic]

Thank you Jason - I await Friday's Block test with interest - as, I fear does my Bank Manager.....

 

[djtaylor]

If it turns out you need a head off job, is DIY an option?

It's not that bad a job if you have a reasonable tool set.

David.

 

[ben hall]

I just had my head gasket done - 277 quid from a reputable independent, so not too disastrous.
100 quid for parts: gaskets - head, inlet, exhaust/turbo; cam cover sealant; coolant, and the rest for 5.5 hours labour.

good luck.

 

[AndersonDic]

Update:-

According to my local independent, there's no head gasket issue with my car.....as the block test revealed no traces of gases in the coolant.
I was advised that it might be the injectors...consequently I have bunged in a can of injector cleaner. I do SO hope that that's all it needs....
"Several applications" MIGHT, apparently be needed.
Does anyone have any experience of these injector cleaners? I suppose it depends on the level of "blockage"....???

Regards,

Richard

 

[Blackstealth]

Originally posted by Alton Aero:
[qb]I was advised that it might be the injectors...consequently I have bunged in a can of injector cleaner. I do SO hope that that's all it needs....
"Several applications" MIGHT, apparently be needed.
Does anyone have any experience of these injector cleaners? I suppose it depends on the level of "blockage"....???
[/qb][/b]

I had a problem with my 2.3T running on somewhere between 1 and 4 cylinders on cold and damp mornings a while back. Two good doses of injector cleaner (100ml added to a full tank of petrol on both occasions) seems to have solved the problem tho' (touch wood).

Outwardly the problem sounds identical to the one I was suffering only I had to run the engine for 5 minutes or so before it started running smoothly.

 

[AndersonDic]

let's hope one or two doses does the trick!
It may be a while before I see the improvements!
Cheers,
Richard

 

[johncc]

Another alternative - I took my injectors to a Bosch service centre to get the injectors cleaned, the spray patterns checked, and check for leaks.

The workshop manager actually didn't charge me for this, but IIRC the front desk guy said a few quid per injector.

This is inevitably more effective than a cleaning solution in the fuel tank. Also, if one is knackered, you can replace just that one. Singly they are not very expensive - a set of four hurts a bit.

 

[AndersonDic]

Well - my mechanic finally got round to having a look at the Aero today.
He spotted a slight leak from the head gasket...but also assured me that the factory screws often need re-torquing....so he replaced the cam cover gasket and retorqued.
He then wiped the small amount of leaked oil and said to watch for leaks over the next 5000 miles or so......which of course, I will.
Here's hoping this is an end to the saga!

Cheers,

Richard