Broken Down again!

[Laird Scooby]

https://www.matthewsvolvosite.com/fo...hp?f=1&t=18175

It concurs with when it sounded as if you had no compression. Might be worth mentioning to the garage, and the remedy suggested in the article i linked to.
Perhaps even print it out and take it into them.

[Rversteeg]

I think the described "lawnmower syndrome" is actually caused by the hydraulic tappets. Not applicable to an 8V redblock.
In a cold engine the oil is relatively thick, which can give a higher lube oil pressures in parts of the engine, because the oil flows back with more resistance. Pressures upto 10 bar have been measured on the hydraulic tappets, which can be enough to push the valve open hydraulically, instead of being lifted by the cam. With all open valves the engine can be rotated easily but will never start. With only one or a few open it will start but not run on all cylinders.
Also the internal of the hydraulic tappets can be partially clogged, causing too much resistance for the oil return.
This problem usually occurs when a cold engine is restarted a few times without warming up in between (“showroom starting”).

[James_N]

This bloke seems to be a little one man band. Bit old skool i hope. he's going to tow it down to his garage (only 500 odd yards away from my house!) so hopefully he can have a look at it.

I quickly swapped my air mass meter for my old bosch one which i kept spare yesterday, that didn't fix it. I tried the Ignition module that i purchased off ebay which the guy told me to keep as it didnt work, that didnt help either.

So i'm at a loss really. Hopefully the garage can shed some light on it Thats on top of the fact it needs antifreeze and parts of the exhaust system replaced!

[James_N]

well garage have had a look today, they said it started first time (no need for the tow!) and they took it to the garage and have been starting it periodically throughout the day (he said they have started it around 40 times) and its started first time every time, so WTF is going on

Don't want to have it randomly not starting, especially since the weather will be turning soon, dark mornings driving in, dark nights coming home.

Any ideas? or do i just put up with it?

[Laird Scooby]

Originally Posted by Rversteeg

I think the described "lawnmower syndrome" is actually caused by the hydraulic tappets. Not applicable to an 8V redblock.
In a cold engine the oil is relatively thick, which can give a higher lube oil pressures in parts of the engine, because the oil flows back with more resistance. Pressures upto 10 bar have been measured on the hydraulic tappets, which can be enough to push the valve open hydraulically, instead of being lifted by the cam. With all open valves the engine can be rotated easily but will never start. With only one or a few open it will start but not run on all cylinders.
Also the internal of the hydraulic tappets can be partially clogged, causing too much resistance for the oil return.
This problem usually occurs when a cold engine is restarted a few times without warming up in between (“showroom starting”).

Very interesting theory but two questions - first it also happens to the B2x0 engines so why? and second, how come adding some oil to the pistons via the spark plug hole cure it? I have a theory which James might just shoot down in flames in a bit but from everything i've read about it, my theory also fits.

Originally Posted by James_N

well garage have had a look today, they said it started first time (no need for the tow!) and they took it to the garage and have been starting it periodically throughout the day (he said they have started it around 40 times) and its started first time every time, so WTF is going on

Don't want to have it randomly not starting, especially since the weather will be turning soon, dark mornings driving in, dark nights coming home.

Any ideas? or do i just put up with it?

Had you done several short runs before this fateful morning when it decided not to start James? If so that coincides with my theory.

My theory is that several short runs cause a bit of fuel wash in the bores which will lead to a temporary loss of compression. A Leaky injector (or even set of injectors) can also contribute to this.
If the engine is warm enough to just start getting tight on the piston rings when this fuel wash occurs, they could get slightly stuck in the lands so that next time it has a cold start, there's very little compression.

The resultant fuel wash from this non-start operation would be enough to free the rings off again so they expand to where they should be when cold and hey presto, it starts up as normal until the cycle of several short runs happens again.

If my theory is right about a few short trips before this happened then i'd suggest an oil/filter change (if you haven't done one recently) followed by a good Italian decoke.

[James_N]

Hi Dave,

its my work car so it does 15 miles there and 15 miles back a day, so 30 miles a day, 3 times a week

I will say the car hasn't had an oil and filter change for a while. It does use oil and it did have a slight leak for a bit so i've kept topping the oil up with fresh as and when required but i think i'll get a new Volvo filter and oil and change that. its had everything then, as the sparks and leads have been done already.

[Laird Scooby]

Hmm, old oil getting thin, not clinging where it should, could possibly have a similar effect.
Also when fresh oil is added as a top-up it quickly takes on the properties of the old oil still in the engine, in other words by adding new oil to old oil you make the new oil old.

An oil and filter change shouldn't do it any harm and could well help improve matters.

[James_N]

Originally Posted by Laird Scooby

Hmm, old oil getting thin, not clinging where it should, could possibly have a similar effect.
Also when fresh oil is added as a top-up it quickly takes on the properties of the old oil still in the engine, in other words by adding new oil to old oil you make the new oil old.

An oil and filter change shouldn't do it any harm and could well help improve matters.

I'll get this done ASAP is it hard to do myself. I dont have any ramps or anything, looks like the oil filter has to be accessed from underneath?

Otherwise i'll just get the same garage to do that perhaps.

[Laird Scooby]

Apart from adding the fresh oil afterwards, the whole job is done from underneath.

You'll need to invest in a pair of ramps or a jack and axle stands, an oil filter wrench, drain pan and something to undo the sump plug with. I can't remember what sort of drain plug is on the B230 so can't advise on that one.

Either that or get your local garage to do it.

[James_N]

I'll perhaps get the garage to do it. Hopefully a good going over will fix the problems.

Thanks Dave. Its had new spark plugs, HT leads, Air mass meter.

I'll get a new air filter (does it matter that all of the clips on my airbox lid are broken) would this make any difference?

I'll get oil and filter changed and anti freeze sorted.

Am i missing anything else that potentially needs doing?