Compression Problems

[swanny1970]

Hi All

 

Been having a problem with intermittent loss of power issues for the past couple of months. I have posted a few topics on here and had great advice. It has been gradually worsening over the past 2 weeks and so I rang a mechanic who offered an hour of his time and a diagnostic test for

[Bigjeeze]

I would get another compression test - just to confirm the first - If it comes out the same wasy then the head gasket is certainly the first and easiest option. Once you get the head off you will quickly see if the gasket has gone - if not then start suspecting valves etc.

 

Good luck!

[Pud]

It sounds like head gasket between cylinders 3 & 4. All the compression is going out of the adjacent cylinder on the compression stroke. At low revs it will be ok as the engine will be under little load, as it is when doing 70 mph.

 

Would be worthwile have the valves cut back in whilst the head is off.

 

If it was rings, oil pressure would be high resulting from compression entering the oil system and or grey smoke from exhaust.

[swanny1970]

Hi and Merry Christmas :rolleyes:

 

Thanks very much for the replies and advice Bigjeeze and Pud, it was extremely helpful. From what you have both written it really sounds like it is going to be head gasket, but will check everything else whilst the head is off. Not getting any grey smoke from the exhaust, so that is a good sign!! Would it be ok if I need any more help if I PM you guys? Going to be doing this job myself with a friend (who has done this many times) so feeling pretty confident about doing it. Really appreciate the help, this forum is a life saver!!

 

Merry Christmas and all the best for a prosperous New Year

 

Kind Regards

 

Peter

[Beyond Help?]

There can be a lot of confusion about head gasket symptoms as there can be many, and you can get one or more of them. But as said by others, if your getting little or no compression on two adjacent cylinders then the the gasket has almost definitely failed between them. With this kind of failure you would get no other symptoms than bad running or rough idle and perhaps starting problems. No gasses in the water, no oil and water mixing etc.

 

This needs sorting ASAP or you will be looking at stripping the head and having it skimmed as a hot spot can form where the missing gasket sits causing damage to the mating faces.

[Beyond Help?]

Hi and Merry Christmas :)

 

Would it be ok if I need any more help if I PM you guys? Going to be doing this job myself with a friend (who has done this many times) so feeling pretty confident about doing it. Really appreciate the help, this forum is a life saver!!

 

Your best bet would be to post on this thread and PM people to let them know you have put a new post up.

[swanny1970]

Hi Beyond Help and All

 

You mentioned in your post about getting the job done ASAP otherwise the head could possibly need skimming - is there a way to tell if I will need to get this skimmed or not? Definitately sounds like head gasket problem, getting bad running and intermittent rough idle along with the compression problems in 3 and 4. Thanks in advance.

 

Kind regards, Peter

[MadBaz]

I believe you must not skim the head on 2.0/2.3 engines. I'm not sure why, but TIS and Haynes do stress this.

[Stevoo]

When you take the head off, id reccomend getting it pressure tested for any crack.

When your car losses power does the Engine management light flash?(yellow symbol in speedo unit)

 

You can do what we call a "Bore Wash"

Take the spark plugs out of 3 & 4 hole, and put a small amount of oil down the plug hole, bout 2 teaspoons full. Then re fit spark plugs and un plug lead no.5 to coil pack then crank engine over. Re fit and see if that temporaily fixes the problem.

This did on my mums fiesta for a while but the head gasket did need replacing in the end.

[swanny1970]

Hi All and a Happy New Year :P

 

Right, firstly, thanks to Bigjeeze who suggested getting another compression test done. I bought one from Halfords yesterday, took all the plugs out, removed fuel pump fuse, screwed the compression tester into each chamber and took note of the readings. Bearing in mind when the mechanic did this, 1 and 2 were fine, 3 had no compression and 4 had a tiny amount - all 4 of them had full compression when I did it. Did what it said in the Haynes manual to a tee, cranked the engine for several seconds to get an accurate reading, but it only took 2 and a half cranks to get to full compression. Redid the test, just to be sure and got full compression for a second time. Baffled as to why the mechanics one was different? Am now suspecting that the head gasket is not the problem (hopefully!) Was about to dive right into the head, so again, huge thanks to Bigjeeze for putting me on the right track. With there being full compression in all 4 cylinders, am I right in thinking that it will not be the head, pistons or valves? Possibly thinking along the lines of air intake leak or maybe faulty coil pack?

 

Symptoms are :

 

Intermittent hesitation on acceleration

Intermittent kangarooing

Intermittent rough idle

 

If I keep the car at around 2000 rpm, quite often it will run like a brand new car, but on occasion, it will produce the above symptoms. Am thinking of starting from scratch again - renewing sparks (platinum ones) and HT Leads. A mate of mine who owns a motor factors is ordering me some new coil packs which I can return if it proves to not be them (which is really helpful!). Going to also check the inlet manifold gaskets and the manifold itself for a crack. Any pointers that you guys can give me would be greatly appreciated. Thanks to everyone who has replied, really do appreciate all your help and input.

 

Kind regards,

 

Peter

[Beyond Help?]

I am going to stick my neck out here. An old con used to be not to screw the compression tester fully home and get a low reading. Were you with the mechanic when he did the test? If so then it is possible he was trying to pull that (old) stunt.

 

Coil pack has to be favourite for the next thing to check.

[swanny1970]

Hi Beyond Help

 

I was with the mechanic at the time, but couldn't clearly see what he was doing in the engine, so that is a definite possiblity. The thought of a con crossed mine and my wifes mind yesterday too after I had done the compression test myself, especially as the mechanic said "You have no compression in 3 and 4, it's probably head gasket, I would sell the car mate" and was pretty keen trying to convince me to sell the car - maybe he was wanting to make me an offer!!

 

Hopefully getting the coils today to try, so will let you know. Thanks again for the tip and advice, learning so much from the advice from this forum, hopefully will be able to help others out too.

 

Kind regards

 

Peter

[swanny1970]

Hi All

 

Sorry for the late reply, PC been in for repair (seems everything is breaking down all at once!)

 

Just an update, replaced the coils, HT leads and spark plugs, so much more power now, about 95% better, although still a slight hesitation - but I will start a new thread about that one as it relates to wiring!! On closer examination of the coils, I found two small splits where the connector fits onto the body of the coil. Just wanted to thank everyone for all their help and advice, wouldn't know what to do without this forum!!

 

Kind regards,

 

Peter