hpdi cooling- waterpump-flushing help

[dstarok]

Hi all. I have 2- 2002- 150 hpdi's which had rebuilt powerheads installed by previous owner and have less than 20 hours. I rebuilt both waterpumps with all new parts. One engine (starboard) has given me an alarm on muffs once but not when on the water. Today the one engine (starboard) gave a temperature alarm on the water, I limped along on 1 engine for about 20 minutes kept turning on the key to see if the alarm went away. finally after 20 minutes the alarm went away and I started it and it and ran fine. After getting home I went to flush the engines and the starboard engine didnt have any water coming out of the pee hole. (on the water it did) Port engine does fine, pee hole squirting right away, both in water and on muffs. Do these motors have to heat up for a while to get water from pee hole? It's 80 degrees here so shouldnt be too cold to start out.
When I connect the hose to the flushing port on the starboard engine there IS water coming out of the pee hole.I have also had this motor seem to be running in safe mode a couple times, no alarms then. Turned it off and restarted it and ran fine. I found the oil linkage was open too far on that engine and adjusted it to the .020 gap last week. It had used about twice the oil that the port engine had used.
thanks for any ideas!
Dave

 

[dstarok]

After doing some reading I am thinking thermostat and/or poppit need replaced.

 

[seasick]

After doing some reading I am thinking thermostat and/or poppit need replaced.

There seems to be some conflicting data here.
I agree that a poppett stuck can cause an overheat situation at low revs. Try checking that first. The stuck poppet will not cause an overheat at speed though. If indeed you overheated at speed, it is something else.
Now, I am pretty sure that an overheat condition will not switch the motor to limp mode. Only low oil in the main engine tank will do that. The fact that by adjusting the oil sync linkage reduced the condition, tells me that you have an oil flow restriction. That is often due to a clogged oil screen or a bad oil pump.
Good luck

 

[BobP]

If you are running the HPDI presume saltwater series motor on proper muff with proper hose pressure and vertical as I expect on the dry dock(trailer) the hole will pee and never sound an alarm idling that has to do with over temp until the cows come home. Are you sure it is over temp? How do you know? When you shut the motor off once it alarmed, did you pull the cowl right away and feel the heads both banks one at a time, around each of the plugs areas surrounding the plugs? How did it feel, each bank on the V and then comparing the both banks?

The pee hole may be plugged easy to check piece of single strand wire like copper stripped or trolling wire. Pee nor its hole has nothing to do with over temp, its just s a cheap way to show pump has lift pressure several feet. If hole is plugged means nothing. Flushing means nothing.
Are you sure you did pump job correctly ? When was last time T stats were replaced, when and what did each of the two look like ? Describe.

Putting the motor/boat in water doesn't mean anything vs on the trailer.

Answer the questions above paragraph unless all is well.

(Rebuilt powerheads, why ? Both ?) What's that about?

By the way, above IMHO.

PS Merry Christmas and Happy New Year to all.

 

[dstarok]

Thanks for the replys.
I believed it to be overheart because of the type of alarm and tach indication. Pee hose was clean, I did stick a small gauge wire up in the hole and no change. Head was hot around top cylinder, on starboard side of engine. Did not compare one side to the other. I believe waterpumps were done correctly, port engine is fine. This is an intermittant problem. I purchased the boat from a distressed owner who had to leave the boat sitting for about 2 years after having rebuilt powerheads installed by reputable shop. I have the reciept for the work. I do not know why that was needed. The motors still needed break-in completed, they only had 3 hours.
I had to do a lot of work to get the boat back to seaworthy condition. I can attach a list if anyone is interested and its allowed. ( It is 3 pages long) Prior to running the boat in the water I ran it on the muffs several times. One of those times it did the alarm. I did the waterpumps after that. It alarmed again one time on the muffs after doing the waterpumps. When I finally launched it to sea trial it and put a few hours on the motor towards the break-in period, it did not have any alarms. I've put about 12 hours on it in 4 trips. Last outing the starboard motor temperature alarm sounded at about 3500 rpm. I let it cool and after about 20 minutes the alarm stopped.
I believe I had limited rpms on the motor twice, (sounded like it wasnt running on all cylinders), but I believe that was due to improperly starting the motor before the initial 3 beeps was done. I shut it off and restarted and both times it ran fine after that. I did remove and clean out oil tanks and filters.
I bought the poppet and thermostats for both motors with the intention of changing them on the starboard motor first and depending on their condition decide whether to change the port motor poppet as well. I believe I will go ahead and change on both motors. I am waiting to get my manual although I have seen an excellent "how-to" on a forum at stripers.
So, I think I'm on the right track but if not with the uncertain history of these engines it certainly wont hurt to change this stuff out.
Thanks again for the replies,
Dave
1988 252 Saifish yamaha 150 hpdi's

 

[dstarok]

OK, so i changed the thermostats and poppet valve (pressure control valve) on the motor that is overheating while idling on hose. They were all pretty corroded and needed cleaning/replacing. (Also replaced the hose from poppet to block and connector to block as they broke while removing poppet valve.)

Removed and cleaned out the cooler on the rectifier/regulator, it had a lot of crud in it.

You're probably not surprised that the motor still overheats while idling on the hose. The top starboard (#1) clyinder felt much hotter than the rest, could barely touch it compared to others. The other motor doesnt have this problem, so I believe the hose pressure and connection is sufficient.
I guess my next step is to check the water pump to make sure I didnt screw anything up when I did the water pump service.
Any Ideas?
Thanks,
Dave

 

[dstarok]

The fact that by adjusting the oil sync linkage reduced the condition, tells me that you have an oil flow restriction. That is often due to a clogged oil screen or a bad oil pump.
Good luck

I adjusted the oil linkage only because I read about what it should be, and found that motor's adjustment to be out of spec. The gap was about .25" instead of the .02" spec causing the motor to use way to much oil. I was not expecting it to, nor did it, change any of the symptoms.
Thanks,
Dave

 

[dstarok]

So I decided to take another look at the poppet valve and the spring. I took everything off to get at it and when I took the housing off I don’t see the valve! When I was working on it I was rushing and trying to get it done in the dark with a drop light and it must have slipped out when I was trying to wrangle the housing gasket and screws together. It was lying in the bottom of the pan. I reinstalled everything, that poppet is real tricky trying to make sure it’s not a little cocked when putting it together. Test flush on muffs and its pumping better than the other engine, no high temp, and life is good! I feel stupid admitting this but maybe it will help someone else.

Now to perform same maintenance on the other motor!

Wife is complaining I’m spending too much time piddling with the boat. What are ya going to do. I enjoy it and get satisfaction from solving problems. Oh yeah I save a lot of cash too. Oh well.

Thanks for the help,

Dave