Breathing a bit heavy

[D366Y]

Evening all, thought I’d take the car for a blast after spending the day fitting my new rocker cover and it looks like she’s breathing a little heavy - not loads but I figured it was a good time to check for any leaks etc. Since I’d just fitted it.

Looks like some oil is coming up through the cap on the rocker - any ideas on what causes this? Time for an oil and filter change...?

[Paul G]

Hi Danny. Check your PCV valve rattles and perhaps give it a good clean with a bit of brake cleaner or similar. The PCV is located on the side of the cylinder block under the inlet manifold and behind the distributor. Also check that the rubber o-ring on the filler cap seals correctly.

It may be worth trying an oil change using some 20/50 oil.

If none of these work I'm afraid your piston rings may be getting tired and causing the crankcase to pressurise. To extend the engine's life without the oily mess you may have to swap to the baffled rocker cover that I gave you to stop the oil being chucked out of the filler cap.

[Mr B]

Hi Danny,

A compression test will normally reveal any problems that could be deemed as serious mate.

Wayne

[D366Y]

Thanks guys, I had it compression tested a couple of weeks ago and 2,3,4 were all at 125, but 1 was down at 80 but it runs...

I'll check the PCV as well thanks for that suggestion, the filler cap definitely seals bloody tight! I pushed it on and am struggling to get it off again

I was thinking about changing to the Valvoline 20/50 stuff as I've just been topping up with 10/40 for years.

Was hoping to avoid having to do the piston rings as it's a bloody big/annoying job

[stevemarl]

I had it compression tested a couple of weeks ago and 2,3,4 were all at 125, but 1 was down at 80 but it runs

There`s your answer Danny, those are extremely low readings, should be about 160-180ish. So even if your PCV is not clogged, there will be so much blow-by it`s pressurising the crankcase. If you could run another compression test after putting 5ml of oil in the bores, that will prove wheteer it`s rings or not. As I suppose it IS just possible it could be badly worn valves or head gasket?

[D366Y]

I had it compression tested a couple of weeks ago and 2,3,4 were all at 125, but 1 was down at 80 but it runs

There`s your answer Danny, those are extremely low readings, should be about 160-180ish. So even if your PCV is not clogged, there will be so much blow-by it`s pressurising the crankcase. If you could run another compression test after putting 5ml of oil in the bores, that will prove wheteer it`s rings or not. As I suppose it IS just possible it could be badly worn valves or head gasket?

Well that's not good

I'd hope not a head gasket as that was only changed about 2years ago, but then again that would be the story of my life...

What it really needs is to come out and be stripped down and painted like Andrew's shiny shiny engine because currently the whole thing is caked in oil and sludge, but that will be crazy expensive, take ages and I like driving it too much

[stevemarl]

A herad gasket is nothing compared to rebore, pistons, rings... and then it`d be silly not to put new shells in at the same time
I would first get another compression test done, this time with a bit of oil in bores (as it temporarily seals leaks) and if the comp increases significantly then it`s rings - but at least you know. If not, then it`s `only` a head problem.
TBH, if it IS rings you may be better off getting a new engine as unless you can do it yourself it won`t be worth it.

[stevemarl]

`Rings` by the way doesn`t usually mean just fitting a new set of piston rings, usually the bore will be worn so you`ll need a rebore, then oversize pistons to suit, rings et cetera. It all adds up.

[Mc Tool]

Your better off buying a runner , even if its a bit tired and suitably cheap ,put that into your car and then fix the original one you have as funds permit .

[D366Y]

Thanks guys, will have to look into all this stuff then I guess - lucky I recently won the lottery

Cheers
Danny

[Bug]

I may be missing something, but I feel maybe the suggestion of it being worn valves causing the lack of compression is, in this particular case, maybe not pertinent.
If it is causing the crankcase to pressurise and blow oil out of the filler cap then surely it must be the rings/bore?

Unless that is an unrelated issue? As in; head issues lowering compression PLUS PCV blocked causing oil from cap.

[Paul G]

I may be missing something, but I feel maybe the suggestion of it being worn valves causing the lack of compression is, in this particular case, maybe not pertinent.
If it is causing the crankcase to pressurise and blow oil out of the filler cap then surely it must be the rings/bore?

Unless that is an unrelated issue? As in; head issues lowering compression PLUS PCV blocked causing oil from cap.

100% It is worn compression rings allowing said compression to leak from the combustion chamber down into the crankcase so pressurising it and blowing everything out of the top of the engine. Even a new PCV valve cannot deal with this amount of "blow by". A compression test (both wet and dry) and a leakdown test is needed.

Like I said in my first post, a baffled rocker cover as fitted to later 205 engines would extend the useability of the engine but not cure the overlying problem.

[stevemarl]

I may be missing something, but I feel maybe the suggestion of it being worn valves causing the lack of compression is, in this particular case, maybe not pertinent.

Apologies, I`d just got tunnel vision & gone down the low CR route and lost the context Obviously that can`t cause the pressurisation: I suppose I was trying to give him hope that it itself (low CR) may not involve rebores etc...

Unless that is an unrelated issue? As in; head issues lowering compression PLUS PCV blocked causing oil from cap.

(I did, twice, though say he should do another compression test, " this time with a bit of oil in bores (as it temporarily seals leaks) and if the comp increases significantly then it`s rings - but at least you know. If not, then it`s `only` a head problem." before anything else as that would prove beyond doubt.)

[D366Y]

For the last few days it's been OK - I pushed the cap on a bit more as I remembered that I'd tried to take it out again and couldn't get it off fully

Will have to keep an eye on these things as the low compression on cylinder 1 does mean it will need some love eventually

Cheers
Danny

[Bug]

For the last few days it's been OK - I pushed the cap on a bit more as I remembered that I'd tried to take it out again and couldn't get it off fully

Will have to keep an eye on these things as the low compression on cylinder 1 does mean it will need some love eventually

Cheers
Danny

If you rev it higher it won't have time to lose compression.
As an added bonus, when the con rod exits the block, you won't get oil coming out of the filler cap any more either.





This IS a joke. Please note, this most definitely IS a joke. Don't do it!!!!!!!!

[Mr B]

For the last few days it's been OK - I pushed the cap on a bit more as I remembered that I'd tried to take it out again and couldn't get it off fully

Will have to keep an eye on these things as the low compression on cylinder 1 does mean it will need some love eventually

Cheers
Danny

Any serious amounts of blue smoke coming out of her exhaust?

Wayne

[D366Y]

For the last few days it's been OK - I pushed the cap on a bit more as I remembered that I'd tried to take it out again and couldn't get it off fully

Will have to keep an eye on these things as the low compression on cylinder 1 does mean it will need some love eventually

Cheers
Danny

If you rev it higher it won't have time to lose compression.
As an added bonus, when the con rod exits the block, you won't get oil coming out of the filler cap any more either.





This IS a joke. Please note, this most definitely IS a joke. Don't do it!!!!!!!!

Too late - I've been revving the nuts off it!!

[D366Y]

For the last few days it's been OK - I pushed the cap on a bit more as I remembered that I'd tried to take it out again and couldn't get it off fully

Will have to keep an eye on these things as the low compression on cylinder 1 does mean it will need some love eventually

Cheers
Danny

Any serious amounts of blue smoke coming out of her exhaust?

Wayne

None that I've noticed to be honest Wayne - I'll check when I leave work in a bit but I'm pretty sure I've not seen any

[Mr B]

It's just hard to imagine the engine running ok with such low compressions in the cylinders especially the cylinder that only has 80psi, I would have thought that particular cylinder would be misfiring all over the place or even dead.

As others have said though run the compression test again and do a wet test as well, some things to bare in mind are:

Do the test with the engine hot
Crank the engine the same amount for each cylinder
Throttle pedal to the floor during the test
Take all the spark plugs out - easier on the battery
And of course use a known to be working properly compression testing kit.

Good luck Dan

Wayne