BMC 1.5 Cooling problems

[wannabefree]

Thanks for this.

 

Yeah it would seem that things are not looking great.

 

There was no blue smoke but there was some white smoke, especially when cold. I guess that would suggest the gasket?

 

So I do a compression test to confirm the piston rings are ok and then assuming they are I need to replace the head gasket at least and possibly the head itself?

 

Is there a way to test the head or is it just a case of look and see if there is a crack?

 

I'll do as you suggest and see what progress I can make. There's no compelling reason to move the boat thankfully.

 

For the record I stopped bidding on that replacement engine on Ebay once bidding reached £451. That's what it went for in the end. It apparently had a smoking problem.

 

Oh well, shit happens, it could be worse...

 

 

 

 

There are basically three ways for exhaust gas to get to the rocker cover : up the valve stems, past the piston rings or into an oilway via head gasket or cracked head. A compression test should reveal the second two, and the first one s usually obvious if the engine is run with the rocker cover off. If the breather is blocked, the crankase will presurise and the resulting "chuffing" when the rocker cover cap is off looks a lot like exhaust, but is mainly air with a small quantity of oil smoke.

 

Are you burning oil (blue smoke in exhaust)?

 

Compression test needs done, IMO

Iain

 

Just seen post 23. Looks like gasket, at least. I'd still do a compression test before taking the head off, though. If only one cylinder is down, the rings are probably OK.

Edited January 4, 2009 by wannabefree

[johnjo]

Don't know if this a sensible price or not but a full gasket set is on Ebay at £46 inc P&P. Item No 250349375493

Good luck and I hope it dosen't get too expensive or stressy.

John

[Eeyore]

Don't know if this a sensible price or not but a full gasket set is on Ebay at £46 inc P&P. Item No 250349375493

Good luck and I hope it dosen't get too expensive or stressy.

John

Do not buy "cheap" head gaskets! A lot of hire fleets had BMC engines until quite recently, they will all tell you the true cost of "cheap" gaskets.

Modern head gaskets will be asbestos free, and usualy come with thier own fitting instructions which will differ from the original fittment.

I hope the problem is not terminal.

Steve

[alan_fincher]

Do not buy "cheap" head gaskets! A lot of hire fleets had BMC engines until quite recently, they will all tell you the true cost of "cheap" gaskets.

Modern head gaskets will be asbestos free, and usualy come with thier own fitting instructions which will differ from the original fittment.

I hope the problem is not terminal.

Steve

Yo'll probably pay no more if you go to one of the three or so companies who specialised in marinised BMC 1.5 or 1.8 diesels.

 

For example ASAP Supplies online price is £38.59.

 

See here.....

 

http://www.asap-supplies.com/store_images/...g&desc=HEAD GASKET SET BMC1.5T90 CUPVALVESEAL<br><div align=left>For all BMC 1.5 diesels which have the later shroud type valve seals. Contains the gaskets, seals and washers required to carry out a head gasket change on base engine. Does not contain any marinised component gaskets</div>&asap=

Edited January 4, 2009 by alan_fincher

[Iain_S]

There was no blue smoke but there was some white smoke, especially when cold. I guess that would suggest the gasket?

 

So I do a compression test to confirm the piston rings are ok and then assuming they are I need to replace the head gasket at least and possibly the head itself?

 

Is there a way to test the head or is it just a case of look and see if there is a crack?

 

White smoke can be unburnt diesel, or water. (Or both!) Sometimes, holding a plastic or paper plate or similar in the exhaust smoke can help to distinguish between the two, from what condenses on the plate.

 

I would do a compression test, although from the coolant in the oil it looks like the head will have to come off. I take it there isn't any other place the oil and water are in close proximity, like an oil cooler?

 

It's well worth trying to get hold of a workshop manual for the engine, which will have all the torque settings, etc. Once the head is off, it and the gasket should be examined to find the problem. If there is a leak from a cylinder. it's usually pretty obvious, but oilway/water jacket leaks can be more difficult to spot. especially if the gasket disintegrates on removal. Some gaskets use a rubber "O" ring on the oilways, but I don't know if the BMC uses one. Any cracks in the head will show up when it's cleaned off. The other check on a head is to put a straight edge over it, both lengthways nd across. to make sure it's not warped. While the head is off, take the valves out (Make sure you put them back where they came from!) and check valve seats and also the fit in the valve guides.

 

Iain

[wannabefree]

Thanks for the advice everyone.

 

No - there's only a gearbox oil cooler.

 

I'll let you know how I get on, although I'll not be attempting any of this for some time.

 

 

White smoke can be unburnt diesel, or water. (Or both!) Sometimes, holding a plastic or paper plate or similar in the exhaust smoke can help to distinguish between the two, from what condenses on the plate.

 

I would do a compression test, although from the coolant in the oil it looks like the head will have to come off. I take it there isn't any other place the oil and water are in close proximity, like an oil cooler?

 

It's well worth trying to get hold of a workshop manual for the engine, which will have all the torque settings, etc. Once the head is off, it and the gasket should be examined to find the problem. If there is a leak from a cylinder. it's usually pretty obvious, but oilway/water jacket leaks can be more difficult to spot. especially if the gasket disintegrates on removal. Some gaskets use a rubber "O" ring on the oilways, but I don't know if the BMC uses one. Any cracks in the head will show up when it's cleaned off. The other check on a head is to put a straight edge over it, both lengthways nd across. to make sure it's not warped. While the head is off, take the valves out (Make sure you put them back where they came from!) and check valve seats and also the fit in the valve guides.

 

Iain

[marmaduke]

Hi,

 

Just been reading this thread with great interest, as i've just bought a boat with a BMC1.5. How did you get on in the end?

 

M