another warm engine

[Pascal]

no real need for a tank, is there? couple of sundays ago i was awaken by an HHH blinking on all A/C controls... always pleasant at 7am on a hot sunday... strainer was clear but very little flow with the seacock and strainer open.

had to go for a swim... a mask was all it took to pull off a plastic bag off the intake.

[Nonchalant1]

Have the same situation that occurred this weekend...Brigadoon (53MY, 8V71TIs) runs at around 170 degrees all day at 1500 RPM. When I throttled up to full power for a "clean-out run", the temps came up on the port engine fairly quickly to the 195 range. Dropped RPM back to 1700 and the temp dropped with it. The Starboard engine temp increased as well at full throttle but never got above 180. T-stats are 160's.

Guess I'll be cleaning the intercooler this week sometime using the method Gen described. The boat does not have the gear cooler on the suction side so that shouldn't be a contributing factor. Water pumps are fine with new impellors and re-surfaced cover plates. When I pulled the original (to me) impellors, they looked to be in good condition with no missing vanes so I don't think there is any junk obstructing the tubes although I don't know what had been done on the boat previously. However, the Eng rebuilds (previous owner) were done with tons of silicone sealer which always makes me nervous considering that most people use too much and it just squeezes out and goes who know where. So I guess I'll pull the RW pipes to the cooler and take a look as well.

Any other thoughts are welcome...

Mike, I know you're a very thorough guy, so this is stating the obvious, but you didn't mention the sea strainers. I can't rely on the glass tubes to see if they're clean because it's too hazy to see inside the basket where it counts. I have to take the baskets out to know they're clean.

Doug

[MikeP]

Doug -
that's an excellent point! I checked the strainers yesterday after we got back - they were fine. I can't check the actual intakes since I don't have any SCUBA gear! But if I did, I would!

[jim rosenthal]

Test ran boat today, with IR thermometer aboard. All the temp gauges now agree; whatever was wrong with them that caused them to disagree "got better". Expansion tanks read 176/178 or something like that. (I was doing this alone). CAT states temp range is 160-195. Upstairs gauges read 190 or 195.
Seawater temp today is 83 degrees F. (well at least it's not C although it feels like it). Evidently according to T&S, my CAT dealer, everyone is complaining about the same thing.
The port one does run a bit warmer and cools off slower. I think this is the HE and will try the Ospho RX (there is no aluminum in the freshwater path). However I also ordered the seals and Orings I need to R&R the tube bundle. I think that's what it's about. I am also going to get a diver to check the intake strainers, we have a lot of barnacles up here this year, but I suspect that's not the issue. Meanwhile, if I keep her speed down, which I hate doing, she does okay. The question is, how much hotter will the Bay get? We could get to a point where she overheats just sitting at the dock- with the engines off

[Traveler 45C]

I think this is the HE and will try the Ospho RX (there is no aluminum in the freshwater path

Jim, you don’t want to run that Ospho through the freshwater system, raw water system only. Correct me if I’m wrong, but I believe running it through the freshwater side will cause heat transfer problems.
You did mean the raw water side, right?

[Captcoop]

Jim, I just helped a friend that had a heating problem with his 3116 and it turned out to be the trans. cooler, it was full of the flakes off the zincs that restricted the flow. I also checked his heat exchanger to see if the flow divider that turns the water on the end oposite of the cooling water inflow was bad. I had that problem with an older Cat engine but his were plastic so they should last a long time. If you haven't pulled the end cap off of your heat exchanger to have a look I will say it is very easy as they have a nice O ring system. I just removed the bolts took a look and fastened it back together with not much trouble. Good Luck

[jim rosenthal]

Yes, I did mean the seawater side, not the freshwater. I've obviously been working too much and not doing enough boating. I didn't think of the trans coolers, I will take a look at those also. And I did get the seals and rings I need to take out the tube bundle and have it cleaned at a radiator shop if need be.
I think the Bay gets this hot every summer. I think what's really going on here is that the cooling system has lost some of its' ability to transfer heat to the seawater, which again points to the tubing bundle. I cleaned the other engine last year and it's not doing this. I think I am just going to have to bite the bullet and pull the HE out. It's just a messy sloppy job to be doing in the heat of summer..but, hey, that's why I own a boat, right?

[jim rosenthal]

An update...I drained the coolant out of the port engine, took out the HE core, and cleaned it, which was a bath in muriatic acid about 1:1 with water, and then a trip to the car wash to wash the outside of the tubes. Then buttoned it up and ran the boat.
It is better....at normal cruise speeds the temp is identical to the stbd engine (I did this alone so I didn't have a chance to check with the IR thermometer). I had to push them to 2600 revs to get the port engine temp to go up, but go up it did- to 200. I backed off, and it went back down. According to the NDBC the Bay temperature is about 84 degrees up here, and where I am it is shallower, which is to say warmer yet.
Bottom line- improved, but not totally normal. However, I have pretty much done what I am able to do with this. I am going to check things out with the IR thermometer, and see what the temp is with that.
Funny, the port engine is always the one that's trouble. The transom is slightly sootier on that side, the revs come up slower, the engine runs warmer- that one is just the prima donna. The starboard one has never given me a minute's trouble. As a friend of mine said, they are sisters- not twins.

[ADaily3224]

Jim,

I was wondering how many hours on your engines. I have the same, 350HP 3116's they just turned 400 hours. Lake Ontario is warm too, 72 degrees, it turned over the other night (up welling) and is now 58. My temps never change no matter how hard I push the engines. Last year I had a Cat tech on board who ran it at full throttle (2,875RPM) for 15 miles, Jeeze I thought these things are coming apart, it was during a PAR check out, and it checked out fine. Temps got to 180 and stayed there. Anyway just wondering what I have to look forward to as the hours pile up. I cruise at 2,300 rpm, very rarely higher, and lately lower because fuel has hit $1.01 a liter in Canada, where I'm pretty much forced to buy it unless I want to check back into the US, Customs are a real pain lately. So far I have only done filters and impellers. No soot, no issues, and not salt water to deal with, at least not yet.

Tony D

[spartonboat1]

Re: the occluded sight glass on the strainer...Groco sells new clear glasses and seal kits. Spending your nickel for you.....