Hotter water and steam coming out of starboard exhaust tip

[Blue Mist 97]

I had basically the same problem with my 502. Steam and warmer water from the starboard tip. Water flow looked good, but it was still 30+* hotter than the port side. I recently replaced my old composite sea pump with a new stainless sea pump and installed a new set of manifolds and risers. While at it, I pulled all the hoses and found a complete vein from an impeller lodged (and laying flat) in the intake side of the oil cooler. It was one piece and one piece only blocking the flow into the cooler. The impeller on my old pump was in perfect condition, so someone failed to backflush the hoses when changing the impeller in the past. I would suggest that you back flush the system from the thermostat back to the sea pump and see if there is any debris. Manually check the oil cooler to make sure there are no pieces of impellers or other debris lodged in the oil cooler tubes (at the bottom) and then clear the hoses back to the sea pump outlet. May not be your problem, but I didn't think it was mine either. Worth a look.

 

[Blue Mist 97]

Deleted, double post.

 

[snowman51789]

i decided to pull the heads and get them checked out. the shop I took them to said 3 cylinders had a leaking intake valve and they suggested doing a complete valve job, I also had them check the fuel injectors, they found that 3 of the 8 fuel injectors were bad, with the valve job, fuel injector check and all the gaskets for me to put back together my cost was $750.

my next question, mercruiser fuel injector are $250 EACH. did some research and found that I could get sierra fuel injectors and the are only $160 for all 8, dose anybody have any experience with aftermarket fuel injectors? do the hold up?

 

[alldodge]

Don't know what "bad" injectors mean. Did they open/close incorrectly, flow test, did not meet minimum 5000 RPM test?

Without knowing the shop which checked the fuel injectors, I'll say injectors need to be tested on a machine which can pulse and flow test them up to at least 5000 RPMs. The fuel screen baskets in most cases need to be replaced because of ethanol fuel, which are cheap.

If the cylinders were getting to much fuel this would not cause an overheat. If they were getting to little fuel, this can cause an increase in heat but also can cause detonation which will destroy the motor.

So if this was a shop which has the ability to fully flow and test the injectors then they would need replacing, otherwise they need to be sent somewhere else for testing

As for Sierra products, I'm not a fan, but they do have some items which do work and will last, I just don't have any which I will advise on. Now we might be able to find some Delco, Bosh or another, but this would take some digging. I would also not get all 8, and only replace what did not meet specs.

What print out on the injectors did you get and can you post?

 

[snowman51789]

the shop that did the head work, sent them out to another shop that flow tested them, they did not tell my why they failed the test the just said the needed to be replaced (they did not in anyway try to sell me injector so I WANT to believe they are not screwing me over). the shop that did the head work is a reputable shop in my area, I didn't try shop around and go with the cheapest price I could get.

I am new to working on v-8 internally. did not know I was normal to get a sheet telling me info about the test of the fuel injectors. I will try to call the shop on Monday and get the info.

if the fuel screen basket was clogged or needed to be clean, would I visibly be able to see the dirt in it? I did closely visually inspect the screen baskets before I sent them out and they appeared to be clean.

 

[alldodge]

Not throwing stones at anyone, but marine injector testing is different then automotive injector. So if the shop does mainly high quality automotive work they just may not know a good shop for marine injectors.

 

[snowman51789]

I found out about the shop threw other boaters that used him for various types of engine work on there boats. when I got to his shop, and had some conversations with him he told me he dose automotive and marine work. about 1/3 of his work was marine. he also rebuilds motors for a few different charter boats in the area.

again im new to v-8 engines, I do understand that marine engine must endure different types of loads then automotive engines but just for my education, how are marine fuel injectors tested differently then automotive fuel injectors?

 

[alldodge]

Auto spends most their time below 1800 rpm and light load. A boat spends its time above 1800 rpm and heavy load. I guy can say he does mostly marine work which means he can work on a boat but does not mean he knows the full realm of what a marine motor needs. Just seen way to many name only marine certified techs here.

Many marine motors operate and different fuel pressures then auto's

Not seeing any kind of a test sheet does not provide any good feelings. Again not throwing stones, but no test data to me tells me it didn't happen.

Sure hope you got all your injectors back and your know which ones did not pass test. I would be willing to send them to a place and see what they tell me on my dime.

All that siad, if your happy with what the they are doing, great, stick with them. All I'll say is so far is I have seen nothing which is, or is not causing any possible problem mentioned so far

 

[snowman51789]

I did receive all 8 fuel injectors back and the 3 that tested bad were packages separately and tagged.

Can you suggest anybody that specializes in testinf marine injectors?

earlier you said it was possible to cross reference my injector to a bosch or delco, how would I go about doing that?

If I am unable to get any paper work about the test, I will want to send them out to have them tested properly.

You mentioned that if it was running lean as a result of a bad fuel injector that there would be signs of this on the pistons, I read about this in my merc manual and saw no signs of any detonation issues.

 

[alldodge]

I did receive all 8 fuel injectors back and the 3 that tested bad were packages separately and tagged.

Can you suggest anybody that specializes in testing marine injectors?
I can, and will send out at my own cost to test and would send to a guy that goes by BUP on OSO to TX

earlier you said it was possible to cross reference my injector to a bosch or delco, how would I go about doing that?
Said we MIGHT (post 24) be able to find others. Would need to start with which ones are installed (part numbers) then start the search

If I am unable to get any paper work about the test, I will want to send them out to have them tested properly.

You mentioned that if it was running lean as a result of a bad fuel injector that there would be signs of this on the pistons, I read about this in my merc manual and saw no signs of any detonation issues.
No detonation then it wasn't running lean, guess we are back to finding the steam issue

Right now I'm not certain we have a problem until we know what is getting to hot

 

[krakatoa]

And don't be too concerned about not being able to keep your hand under the water. Even at 160, you will get burned. Try sticking your hand in a freshly brewed pot of coffee and see how long you can keep it there.

thasts a good one.....

 

[krakatoa]

the shop that did the head work, sent them out to another shop that flow tested them, they did not tell my why they failed the test the just said the needed to be replaced

just following this thread looks interesting and great info,

IMO If they cant explain or tell you why they failed doesnt look good to me..... is like the shop leave you throwing punches in to the air

 

[snowman51789]

I agree. however if they were trying to rip me off, you would think that they would have tried to sell me new fuel injectors, on the phone they suggest me to a few local shops to guy new injectors but they also suggested me trying to find some online.

thanks to this thread I have done a lot more in depth research and found that there are several ways that an injector can go bad. the only test that I was able to do was and ohm test, and all 8 tested good. I was unaware that I should have been giving a sheet about the tests.

I plan to call the shop and get some more info tomorrow. how ever we are leaving for Florida in 2 weeks so I would like to have a "plan B". so if by chance the injectors do turn out to be bad, are there any quality after market brands out there that anybody could suggest?

thanks

Dave

 

[alldodge]

Motor serial numbers are always best to look up parts. Your injector is probably part number 805225A1 which are about $220 each. There have been others which has found ones which will work, but this would take some more looking. post your question on OSO and you should get some feed back

 

[snowman51789]

My serial niumber is 0l014516, yes you are right about the fuel injector number. I have looked into oem fuel injectors, but as mentioned I am looking to save some money because next winter I plan on completely stripping the motor and building the monster that I've been planning for a few years. 1 of the mods I'm planning is high performance injectors, but right now I do not have the funds for the injectors I plan to buy this winter. So I'm just looking for something cheap but reliable enough that they won't blow my motor before this winter.

 

[alldodge]

Your injectors are the same ones used in my motor (502 MPI built) which is producing 530 HP. I'm using a Gen 2 cool fuel and supplying 40 PSI. Mentioning this because the ones you have can provide even more HP then what I have now without changing them.

To find some other options, suggest posting on OSO and see what those folks have to say.

 

[snowman51789]

Ok,
so, I got side tracked when I found out my heads were bad. I got the heads installed and the boat is running great. When I took it out it was still blowing am excess amount of steam out of the port exhaust and the water coming out was very hot, notabley more then the starbord side.

When I got back, I decided to pull the thermostat housing and put a house in there and open the lower drain plugs and back flush the hell out of it. I also baals flushed the oil cooler. I put a Pan under the lower drain plugs to hopefully catch and sand that came out so I could see if anything was coming out. I got about 1-1½ shot glasses full of sand. I didn't think that was enough to cause that much of a problem.

So I then put everything back together but left the thermostat out and I ran it on the muffs, bliping the throttle every so often. I also put pans under the exhaust hoping I would be able to see if any sand came out, and it did. It was clear that sand was coming out but hard to measure because of the thru haul exhaust spraying water everywere.

I then reinstalled the same thermostat that I took out and bingo, no more steam, and the manifold risers felt almost cold top the touch. Also the water coming out the exhaust was noticeably cooler on both sides. I have not ran it on the lake yet so I'm not 100% sure it's fixed but there is definetly an improvement of before and after when running it on the muffs.

​​​I believe that running it with out the t-stat is what cleared it out the most.

​​​​​​

 

[alldodge]

Sounds good