Iveco 8361SRM40 steam problem

"Hello all,

I just found th

"Hello all,

I just found this excellent forum.

I have a problem that some of you guys might be able to give me some advice on.

I have an Iveco 8361 SRM40 (400bhp @ 2400rpm) lately the engine(2000 hours now done) has developed a strange fault. If you drive the boat it is going like a clock right temp, exhaust is clean, starts and stops normally. But when you take the boat out of gear (or drop to almost idle speed in gear) after steaming, after about 30-40 seconds the exhaust begins to steam excessively. The steam possibly smells a little like engine coolant.

She loses some coolant from the header tank, she might take a litre or so after a days running. The expansion tank doesn't hold coolant I noticed this since I changed the water filter at about 1500hours (may be just a coincidence) the expansion tank is dry, if I fill it to the "min" mark it is empty again the following morning.(this was happening well before the steam issue).

The head gasket and turbo are both OK.

Any advice on where to start looking for this problem.

Any advise will be greatly appreciated!!

Jim"

"Hi Jim,
I have these motors

"Hi Jim,
I have these motors also and last year noticed coolant was escaping from an expansion tank. After some investigation I found the radiator cap was sealing the header tank but not the expansion tank so I replaced it and no more problems. Hope this helps. Geoff"

"Hi Geoff,

Thanks for your

"Hi Geoff,

Thanks for your reply.

I sorted the problem soon after I posted on here by replacing the turbo / manifold gasket. At the time I discovered the impeller was also cracked but was pumping water like normal, so that may well have been causing some of the steam, Any mechanic I spoke to was mystified by the problem as it only happened after throttling back to ticking over and it then took awhile to start steaming.

My expansion tank cap was missing when I got the boat it only ever had a small plastic bag with a rubber band covering it, I put a few pin holes in the bag as it needs to be able to breathe, My coolant finds it's own level since I changed that filter above (may have been a slight air lock before?) so the expansion tank is empty when cold with just a little expansion when hot. Even if I fill it to the max it will find this level after a days running.


Jim"