Yanmar 4JH-TE won't crank

[captstu]

How Old is your exhaust elbow? They are rated at about 700 hours on small Jan Mars. If your elbow is older and hasn't been replaced water can be pushed back into the engine causing Hydro lock.

[model 10]

Originally Posted by Badsanta

Lepke, where can I find your auto draining valves? Sounds like just what I need. Thanks

Lawn sprinkler system drain valves.

[leascotia]

Latest update - I pulled a sample from cylinder 4:


To compare, in left-to-right order, the sample from cylinder 4, anti-freeze from top of engine coolant reservoir, and finally diesel from the racor 500 primary. (there is a bit of anti-freeze in the diesel because I pulled it right after the anti-freeze, there's no contamination in the diesel itself. Our marine diesel here is a light green color).


I'm not 100% sure, but that really looks like almost pure salt water in the cylinder. If it had any diesel or anti-freeze in it I'd think I'd see it like I see the anti-freeze in the diesel. So the suggestions to look at the exhaust seem like the next steps.

Lepke - thanks I think your suggestions are where I should look next per above. The drain valves sound like a great idea, going to look into that too.

jkishel - I'll have to go back and look at my notes on the oil consumption (hopefully I can find them). Thinking back, I wasn't topping the oil off every day and last summer we were motoring 6-10 hours every day for like a week on occasions. What would be considered 'acceptable' for a 1989 yanmar (4jh-te) with roughly 2800 hours? The drip pan is clean so I don't think I've got an oil leak anywhere but I'll double check. If it's not leaking then it's safe to say it's being burnt? Any suggestions on what else to look for on oil consumption?

Ndavies - at this point I can safely rule out any starter issues- the engine cranks just fine now and spews stuff all over with great gusto. (besides it's a brand new starter- I was having the problems you mentioned last summer and replaced it, plus see my comments on having a relay installed to handle the small wire problem).

Question - given the gunk on injectors and the fact I don't know how long the (presumably) salt water has been in there - should I be pulling the heads and inspecting the cylinders at this point or is that more trouble than it's worth? If I pull heads sounds like I should also put in a new head gasket?

Lastly here's more pics of the samples if anyone is interested: https://www.smugmug.com/gallery/n-sn9FQN/i-JmCtxfC

Off to the mechanics now with the injectors - fingers crossed they can fit me in sometime this week. Nobody's returned my calls yet today :/

(Oh, one last thing - uploading photos doesn't seem to work - I've had to post them to a separate site then link... not sure if it's something I'm doing or others have the same problem?)

[sailcrazy]

We have a 4JH-TE in our boat....and had a very similar problem a few years ago. Our Turbo blew apart(corrosion and no residual oil to the bearings) after sitting on the hard for about 8 months. The engine sat for another 2 months while I found parts (we were living in the Philippines at the time, and Yanmar parts were not readily available!). By the time I got the required turbo parts, the engine would not turn over-with the injectors in or out! Turned out exhaust water found its way into the #3 and #4 cylinder, corroded the pistons to the liners so completely nothing would break them loose. I had 2 choices...replace or rebuild. I chose to rebuild. It took almost a year to get the required parts,tear down the engine, replace the cylinder liners and pistons, and rebuild the engine. Aside from "rebuilding" the fuel injector pump-without gaskets-the Philippino mechanic did well and the engine has been running great since (after I pulled and rebuilt the injector pump properly). And yes, we did find (and replace) a faulty exhaust elbow. I'd say you are REALLY lucky you got it to finally turn over, and saved yourself a complete rebuild.

[David Hughes]

Originally Posted by Symphony

that Yanmar is also famous for having a weak, thin wire from panel ignition switch to the starter, ask me how i know.

Boy, ain't this the truth...


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[four winds]

You have mentioned the anti siphon loop on the exhaust exit.

But don't you also have an anti siphon loop on the seawater cooling line that feeds into the the exhaust elbow?

Mine is hidden up high behind the galley sink on a 3gm30f. No anti siphon valve on my final exhaust, just the hose routed up high to the gunwale and back down to the transom.

[seasick]

Lepke is spot on.

In addition:

Close off your raw water intake until you've completed your repairs and the engine actually starts firing. As well, it would be a good idea to pull your valve cover and check all your valve clearances especially cyl 3-4.

Place oil absorbant pads weighted with towels over the injector ports before cranking. A dab of grease on the raw water impeller. Crank until you have clear cylinders then add a dollop of Marvel Mystry Oil to all cylinders and let it sit for a night. This will really help free up any rings that may have frozen.
If you have bent any rods the valve clearence test will tell.

[YARGO]

My 4JH series engine locked up from water entering the cylinders due to a failed siphon break on the sea water line to the exhaust elbow. Remove it and test it.

[lookinggoodrock]

I had exactly the same problem last year in Exuma. It is the heat exchanger leaking water into exhaust manifold into engine. Unfortunately the heat exchanger is probably unreparable. Take off the heat exchanger, fill with water via radiator cap. Water will come out of the manifold where it connects to engine. I had to replac manifold. Around $3,000 if I remember correctly. I figure the heat from the exhaust and older antifreeze ( becomes corrosive ) leads to a hole. Sorry to be the bearer of bad news.

[k. michael marquardt]

1. You'll have to recondition the injectors by a qualified mechanic. (There are the valve seats to be checked and the spring tension restored in order to achieve a good spray of fuel at the injecting cycle.

2.Then you need to flush your cylinders with cean lube oil and change oil and oil filter otherwise the internal parts of your engine will corrode and cause more trouble.

3.As for the cause of water entering the system just try to install a bigger water muffler or increase the hight of the exhaust loop, the part that carries cooling water and exhaust.
Auto drain valves for mufflers do not work well if the engine is deep down in the bilge.

[leascotia]

Originally Posted by seasick

Place oil absorbant pads weighted with towels over the injector ports before cranking

Wish I'd had that advice earlier this morning, although I think it would've taken a pretty darn heavy towel. Ah well the engine room needed a wipe down anyway.

So, apparently Yanmar is a dirty word around here - several mechanics pretty much flat out refused to touch it. Guess they're busy with the fishing fleets and don't need any more $. (though the fact that I don't have a big f'ing fishing boat that stops in their yard once a year probably has something to do with it).

I think I found a guy to test the injectors tomorrow so hopefully that checks out- otherwise I'll probably need to send them to Seattle. Was thinking Hatton's but anyone have suggestions?

Another mechanic and myself gave the mystery fluid the good 'ol sniff/taste test. Pretty much straight salt water as best we can tell.

Four winds and Yargo - I suspect a syphon failure too so that's the next place to check (I've been slowly replacing them on my heads and other areas). My main exhaust is up pretty high but doesn't appear to have a vent - I'm going to double check again tomorrow. The smaller loop coming from the mixing elbow has one that is very high (at least 2', probably more, above the waterline). It has a hose running to the bilge, doesn't look clogged but will test tomorrow.

lookinggood - really hoping that's not the issue. Given we didn't find any trace of antifreeze in the cylinders nor in the exhaust drains I think I'm in the clear on that one- fingers crossed.

k. michael - that pretty much sounds like what I had planned. If they test to spec I'll probably put them in and try running it. Otherwise off to Seattle they go. Changing the main exhaust loop isn't really an option- it's up to the cockpit floor, and 2" in diameter. We haven't had a problem in 3 years, and we've sailed in some pretty nasty following seas.

Lastly, I dug up my logs on oil consumption. I'm fairly confident it's not leaking into the bilge (I suppose it's possible, it's very hard to see to the bottom of the sump, it's directly under the engine and blocked by a drip pan, which was clean before this little incident). It looks like it was roughly 16 oz every 40ish hours.

Does anyone else with a similar engine / hours track your oil usage and if so what do you typically see? (so as you don't have to read the whole thread - it's a 55hp yanmar 4jh-te, 1989 vintage, a little over 2800 hrs).

[jkishel]

1. Exhaust - go through the exhaust system component by component; cracked exhaust manifold, clogged mixing elbow, malfunctioning siphon breaker, collapsed exhaust hose(s), and clogged muffler could singly or in combination fill cylinders with sea water. Don't make the mistake of finding one thing wrong then assuming everything else is OK. The "main" exhaust hose should not have a vent, but should be routed as high as possible as you indicate it is.

2. Oil - You are reporting consumption (burning, no leaks) at 1 quart per 40 hours. Many people live with worse than that, especially if the oil pressure is still good and lots of the consumption is due to leaks. If you get the engine running again and it runs OK; good power, high revs, sounds good, no smoke, etc.; you might get quite a few more hours out of the engine. I'd keep an eye on oil consumption, oil pressure and blue smoke though. Oh, and carry plenty of oil.

[jakkum]

If you had tasted the water, just a drop on your tongue, you would have known. Really sweet is coolsnt, sweeter than fresh water. And salt, well you know.
I once had a hydrolock in a Lister 3 JP. Bent the conrod, that knicked part of the cilindersleeve out.
Just one big bang.

[leascotia]

An update then time for some sleep (and some details in case anyone else finds it useful). I finally got the engine running! Definitely a huge relief given some of the other potential outcomes. Thanks to everyone for their input.

The local mechanic tested the injectors and said they performed great so I changed the oil, put them back in, went through the priming ritual and she fired up without much fuss. (I did end up shutting off the seawater inlet while cranking and re-opened it as soon as it caught). His suggestion was to run the engine up to temp with the oil cap off to vent steam. I didn't really see any steam, and the engine didn't cross 212 degrees but it didn't make a mess or hurt anything.

There was plenty of nasty brownish looking water coming out so it definitely needed to be run ASAP - the mechanic I spoke with in Seattle was adamant about that to prevent it from seizing for good. Water cleared up and looked normal after 20 min or so. Let it run for about 2 hours. Gave the dock a good tugging.

I also did an oil change before starting but didn't see any sign of salt water in the oil, nor did I on the dipstick (checked a few times while it was running. I'll change the oil again tomorrow just to be on the safe side.

As to root cause, I traced the exhaust loop and pulled both sides of the vented loop from the exhaust manifold and from the exhaust elbow. A little water came out of the hose from the elbow side, but there was no water in the elbow. Of course plenty of seawater came out of the exhaust manifold (where it should be). Both the manifold and elbow look in excellent condition - no rust and hardly any carbon (I think the elbow was replaced a few years ago as were several of the exhaust hoses - before I bought the boat though). There's no signs of leaking anywhere.

When I went to test the vented loop from exhaust to elbow, I noticed I must've moved the hose that went from the vent to the bilge so it was facing upwards (probably when I put in the new bilge pump several months ago). This sounds really trivial and silly to me but I had a long talk with the local mechanic about the nefarious effects of syphons (he had some good stories). I'll be fastening it properly so it doesn't have low points and always points down, and also labeling it.

So, if it were your boat, what other root causes would you check? There's not really much else to the exhaust system, and the raw water flow out the back was good. No trouble idling either. It always amazes me how sometimes the smallest things can result in such a mess.

Lastly, I think I've found a potential culprit for both the oil loss and the white smoke - the turbo charger. When we were running at 2,000 rpms (we cruise between 2500-2800) I noticed a little smoke coming from the turbo charger. I poked around for a few minutes to see if I could see where it was coming from - looked like the middle where the bearings live. The blower (intake side) was around 105 degrees F, the turbine (exhaust side) was 350 or so. The service manual says both smoke & oil consumption can be caused by a worn seal ring. We throttled back to 1500 and after a few min the smoking stopped. That'll be tomorrow's project.

[bstreep]

I'm an expert at pulling the turbo. I have it down to about 1.5 hours out, then 1.5 back in. Put plenty of towels down to catch dropped parts before they travel to the bilge.

Ez off oven cleaner - the original nasty version, not the "green" version, is great for cleaning. We now do this periodically by just removing the exhaust elbow. It should spin freely.


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