Yanmar 4LH/HTE Head Gasket Replacement

[terrymccann]

Hiya All,
I ran up the engine to charge batteries yesterday and found emulsion on the dipstick and under the oil filler cap. I can't figure out why, as the yacht has been marina bound for months and this seems to have occurred a week ago, when I ran the engine to charge up, as I usually do weekly.

I noted that the engine ran very cold, even after running at half throttle under load for 20 minutes.
From my limited experience, it sounds like the head gasket.

Has anyone got any info on replacing the head gasket without calling in the engineers - I'm rebuilding the yacht on a very limited budget and would prefer to do it myself.

Regards
TerryMac

[iluvteak]

If you lost coolant I'd suggest checking your exhaust manifold for a breach from a water jacket emptying into the exhaust manifold. But that would cause an immediate overheat I would think. Is your oill level higher than the normal oil mark on the dipstick?

[terrymccann]

Thanks for the help.
The oil level is a lot higher but coolant levels are the same and I ran the engine for 1/2 hour last night with both coolant cap and oil filler cap off, to see if heating the sump oil would result in any moisture boiling off and exiting via the oil filler port.
No fumes, no smoke visible and the water temp remained the same on the gauge. ( Strangely enough, I had the same emulsion in the gearbox oil about 3 months ago and changed to oil to a better quality oil and that cured itself??)
Now I'm going to look at the exhaust elbow - which seems in good condition from the outside.

[iluvteak]

Yikes if oil level is up and coolant is the same, that kinda points to raw water in the oil I think. That could be an oil cooler leak too, I tested mine at a radiator shop for $50. Or the mixing elbow is shot and raw water is backing up thru the exhaust manifold and into the cylinders. This is what Ive been told anyway.

I believe you can test the oil for the type of water in it, sea or fresh. I'm not a mechanic and could be way off here on sea water idea. Hope so for your sake. I've just been thru the water in oil issue myself on a 4jh2e.

Good luck, keep us posted pls.

[terrymccann]

Thanks Guys,
Just a bit of feedback:
After removing the oil cooler and stripping it to check the two o-rings, I moved on to strip the raw water pump down and found weeping on the waterpump sealed bearing seals.... Seems that this is where the salt water ingress was.
I cheerfully went off the Yanmar agents in Cape Town and was horrified to learn that a wholesale replacement w/pump was $1411 ex vat! Seems these guys usually deal with International shipping companies needing genset spares and wait like spiders for an unwary victim to attach himself to their net. Local Yanmar owners have no choice but to buy at cost x 10 x10, as they are the official agents in Southern Africa. Interestingly, I managed to find a fellow yottie by the name of Graham Raynor, who has a little pump company in Cape Town called "Pumptech" and Graham rebuilt the whole pump, using locally available spares at a fraction of the cost ($211.00). Thanks Graham.
I absolutely detest opportunist agents, so I guess I'm going back to Nanni or marinised Fords and ditching this revolving lump of scrap iron/aluminium, soonest. Goodbye Yanmar.

[capngeo]

The best way to diagnose ANY coolant issue is a pressure tester! An adapter for a Toyota will fit the Yanmar filler neck.

[iluvteak]

Hi Terry,

Nice troubleshooting on the pump. I heard that could leak raw water into oil and am curious, how did you spot this weeping? Seems if the pump is removed it would be difficult? Pls explain, I have seen a yanmar 3gm raw water pump rebuilt so maybe I can follow your lead.

New 4jh2e raw water pump was $600 here in US. It is sickening.

[bstreep]

Originally Posted by iluvteak

Yikes if oil level is up and coolant is the same, that kinda points to raw water in the oil I think. That could be an oil cooler leak too, I tested mine at a radiator shop for $50. Or the mixing elbow is shot and raw water is backing up thru the exhaust manifold and into the cylinders. This is what Ive been told anyway.

I believe you can test the oil for the type of water in it, sea or fresh. I'm not a mechanic and could be way off here on sea water idea. Hope so for your sake. I've just been thru the water in oil issue myself on a 4jh2e.

Good luck, keep us posted pls.

At some point in time, I'm hoping that Yanmar will either:

1) catch on and decide that maybe this insane, idiotic protection of their distributor/dealership process is ruining their reputation, or

2) DIE dang it DIE.

While I really LIKE the engine, it pi$$es me off to no end to be told who I can buy from and for what price. If I had the time, I'd open a freight forwarding business in Muskegon, Michigan, and for a very nominal fee, forward Yanmar parts for sailors all over the globe.

Come to think of it... I might just do that!

[terrymccann]

Mornin' iluvteak,
Thanks. I stripped the pump down ( beware of the circlip location) and found droplets on the inside of the two "sealed" shaft bearings, which led me to the source of the water. I then reassembled the pump as it was and simply pressurised the water side with a hand pump and thats how I found it. Took an hour or so and minimum head scratching for a delightful change.
Dealing with the South African Yanmar agent is indeed a bitter pill to swallow and Yanmar Japan obviously could'ent give a toss about local extortion either, despite the fact that they liquidated the old company and reopened under another name( keeping the agency, of course)- to avoid paying old creditors.
After being ripped off for years, we can't wait to let go forrad & aft and hoist our cruising main to set sail to the Caribbean, via St Helena.... Libertad is almost ready to go and the red wine tank is full of delightful cabernet merlot. We'll dump the expensive rectangular lump of Yanmar revolving scrap iron pretty soon, now.