Interesting Cause of an Overheated V6

[KCLOST]

I was running out on the lake today, nothing unusual.... After about 10 minutes, I glanced down at the pressure guage and noticed that it was running only at 12-13 psi at WOT compared to the normal 22-23. Took a look at the temp. guage and it was reaching up to 220F (head metal temp.). So I immediately throttled down and the pressure jumped around a bit with the poppet closing, and then it settled down to less than 5psi probably around 2500 rpms and the temperature immediatly increased to near 240F... Didn't get the alarm but quickly shut it down, knew I had a problem... <br /><br />Got it going about 20 min later after running the trolling motor towards the marina. At idle or up to 1000 rpms I had a wopping 1 psi of water pressure... The engine was still running good at least at idle/no-wake speeds, but with only a very weak/constant stream of water with the t-stats opened and running at 180F....<br /><br />I Made it home ok .... Checked compression, all at 115-120 psi. Whooo!..... Checked poppet, OK ... Pulled lower unit and expected to see a fried impeller assuming that maybe I tilted out too much today and lost water causing it to fail.. After removing the water pump housing I was suprised to find that the impeller was in perfect condition. .. But after looking closer at the rest of the pump, look what I found...(Gasket Problem)<br /><br />

<br /><br />Just thought I would let everyone know about this... Amazing that a gasket for a pump cover can almost cause an engine to fail... I'm lucky today... I will diffinitely make sure I torque that cover down correctly next time, as that gasket is only a year and a half old...

 

[rodbolt]

Re: Interesting Cause of an Overheated V6

post a pic of the housing. it almost looks like the lower nylon base has some melt showing under the plate.<br /> good luck and keep posting

 

[achris]

Re: Interesting Cause of an Overheated V6

Good catch KCLOST. That plate does show a bit of grooving around the centre.<br /><br />Year and a half..... Probably time for a kit anyway....<br /><br />Chris.........

 

[cfcstl]

Re: Interesting Cause of an Overheated V6

You mentioned you have a water pressure gauge. Can you post a pic if the hookup on the engine? I am going to buy one shortly and was wondering where the best location would be to get an accurate reading.

 

[achris]

Re: Interesting Cause of an Overheated V6

Buy the genuine kit, it comes with all the necessary adapters and drawings. The pickup for the gauge is right on the top of the block.

 

[cfcstl]

Re: Interesting Cause of an Overheated V6

I would prefer to match the Faria gauges I already have and the water pressure gauge has its own kit. I see a few places the pickup could be installed, but I would like to see how someone else has done it successfully.

 

[KCLOST]

Re: Interesting Cause of an Overheated V6

I'll post a pic of the pressure guage installation tonight...<br /><br />rodbolt,<br /><br />The housing (cover) was in excellent condition...

 

[dajohnson53]

Re: Interesting Cause of an Overheated V6

Originally posted by cfcstl:<br /> I would prefer to match the Faria gauges I already have and the water pressure gauge has its own kit. I see a few places the pickup could be installed, but I would like to see how someone else has done it successfully.

I'm wondering - *if* necessary - you could buy the OEM pickup kit separately. I would guess you could then hook it up to whatever Faria gauge you choose because as far as I know, all waterpressure gauges are fed by a simple hollow tube (similar to pitot type speedos). Sure you'd waste the pickup portion of the Faria kit, but it might be worth it for the ease of installation. A lot of times OEM kits are easier to use than generic kits. I don't know if this is the case here, but it's a thought. Good luck.

 

[KCLOST]

Re: Interesting Cause of an Overheated V6

Here's a pic of the cover and the installation of the pressure guage line at the top of the block...<br /><br />

<br /><br />

<br /><br />I installed a teleflex guage kit. It came with the guage, hose, and several different fittings for various engines, and directions on how to install. However, as you see in the pic you need two fittings to make it work (on my engine at least). The larger one that screws into the block plug hole was one I had to come up with myself. Luckily I work for a company that has a lot of stuff like that on hand. I believe its 3/4" or 1" pipe thread. And also has female threads to allow the smaller elbow fitting to attach to the top as a reducer (the elbow came with the kit).

 

[cfcstl]

Re: Interesting Cause of an Overheated V6

Thanks for the photo. I just checked my motor and I have the exact plug on my 150 so adding the gauge should be easy. <br />btw- do you know what the silver switch box is for with the red and yellow wires next to the pipe fittings?

 

[KCLOST]

Re: Interesting Cause of an Overheated V6

Voltage Regulator....

 

[rodbolt]

Re: Interesting Cause of an Overheated V6

hello<br /> cfcstl<br /> that is the rectifier. KC it still looks like signs of melt indide the cup and at the leading edge. it may just be my monitor. hope so.<br />good luck and post us back with the results

 

[KCLOST]

Re: Interesting Cause of an Overheated V6

rodbolt, I'll check the melt....<br /><br />But that is the voltage regulator not the rectifier... The rectifier is mounted just above the switchboxes, both on the ignition plate (not shown in the picture).

 

[rodbolt]

Re: Interesting Cause of an Overheated V6

yep<br /> I just noticed only one yellow wire.<br /> sorry<br />look carefully for melt at the fwd edge of the cup and where the cup top meets the housing. it may just be my eyes<br />when you lift the plate look closely for signs of the base melting as well. any melt needs a replacement no matter how little it looks.<br /> good luck and keep us posted on this project