Low Compression On ONe Cylinder

[Mulbers]

Hi,

I'v been having problems with my K10 1.0, 4 speed. I was driving down the motorway a few week’s ago about 60 and started to go up a slight hill. The car lost a lot of power and then jolted violently with a sound of air was escaping under pressure.

Carried on driving (this has happened before but kept going fine, so didn’t think too much of it.) it was only until I had stop that the car seemed to be running rough.

Took one lead off at a time and found No. 2 wasn’t firing. Carried out a compression test, all running at 195psi except No.2 which was at 30psi.

Im sure it is not the rings, and the valves (from the rocker head cover view) seem fine.

Has anyone had this problem or similar?

Help would be greatly appreciated. Cheers

 

[Elliot]

It's got to be the compression rings on the Number 2 piston then...

Best bet anyway, would be to stick an MA12 engine in it with a 5-speed box. It's the best thing you could do to the car, as there's so much torque and more power in the 1.2... as I wouldn't bother putting another MA10 in.

-Elliot

 

[Arnold]

Im surprised this thread didnt get some more attention from the k10 experts out there.. however not an expert on it, surely its fixable?

Replacing with a Ma12 isnt always the best solution!! Cost / time etc involved, aswell as obtaining the engine and the equipment to fit it.

 

[Slim]

its always a better bet to fit another engine rather than fix the one you have. you can get an engine for 50 from a yard, and do the complete swap in 2 hours. it costs over 100 for a set of rings, and thats presuming the bores are OK. then you have to mess about geting the head skimmed and all that crap.

put a teaspoon of oil down no,2 plug hole and try a compression test again. If the compression is quite a bit higher, it indicates worn rings, but if its just the same, its the head (allegedly)

otherwise just change the engoine.,

 

[Andrew]

There is so little you can do to an MA engine without it being cheaper than just buying a replacement from the scrapyard. I think the cambelt, waterpump and head gasket set bring it up to over the cost of another engine.

Doing the rings is a big job on an old engine; cam belt off, head off, sump off, conrod bolts off, pistons out, bores honed, old piston rings off, new piston rings on, pistons back in, conrod bolts on, sump on, head on, cam belt on. You need specialist tools and measurement equipment to do it properly, and it just isn't worth it.

With regards to the compression test, the oil thing will indicate if the rings are the cause. Also try backing off the valve clearance adjusters ("tappets"), though it is rare for this to have a sudden onset. Could be burnt valve seats, cracked head, gone headgasket, gone rings and so on.

 

[Ed]

Make sure all tappets are correct, and the rockerarms are tight. Then compression test if still poor try leakdown with teaspoon of oil. If no change you have a bent valve if not then piston rings are seriously shot (not likely).

Ed

 

[Mulbers]

I did try the teaspoon of oil method and didn’t make a difference so I know it’s not the rings.

I think you have just confirmed my fears of it being possible head damage. Which is a bugger.

Never mind. I think I shall be getting a new engine because I really don’t want to get rid of the car. Its that micra bug, it just seems to get ya.

Thanks for your help.

P.S I should have fun striping the old one apart. Anyone for spares??? ha ha

 

[Ed]

CHECK the valve tappet clearences before you do ANYTHING else. It may still be fine yet.

 

[RIK]

it could be your head gasket,

and wot was the plugs like? number 2 oily?

 

[Mulbers]

Thank you for your help but I thought i would bite the bullet and get the new engine i was offered. The old one did burn a lot of oil and and a few other problem, this was the final straw.

I had the head of the old one at the weekend and found it was the exhaust valve on cylinder 2. it hasnt hit the piston but there is a gash taken out of it somehow.

I gave the new engine a good scrub down and is looking very shiny. Iv also cleaned re-sprayed anythig that was rusting in the engine bay. i have before and after pictures if anyone is interested. I also had ago at the air pan modification. Looks good and sounds great. Will post pictures on a different thread.

Cheers.

 

[Speedle]

yeah post some piccy up mate always good to see such things