fast idle when towing

[ichoplin]

I haven't even driven it yet. I would imagine that it HAS to be better. I did let it run in my shop for about 20 minutes and the t-stat housing wasn't even close to 190deg(@130-140 I think). The intercooler was also pretty cruddy. It was easier to clean though due to the larger fins and such.
I'll definitely let everyone know how it is as soon as it gets a good test.
Thanks again,
Ian

 

[ichoplin]

Well, I've only made a couple of trips to town since the radiator cleaning. Have to say, I'm still a little concerned about what I'm seeing.

My temp will still go to the halfway mark and hang out for a minute before it goes back down. I will say that when it does go back down, it moves farther to the left than it did before.

Yesterday, I got back from town and when I pulled into my driveway, my gauge was right on the halfway mark. I got out and shot the t=stat housing w/ an I/R thermometer and it showed approx 210deg. Is this not the best place to aim a thermometer? Am I too paranoid now?

Tomorrow I have a little commute to work(60miles) so maybe I will learn more.

Ian

 

[RVTRKN]

Seeing the pics of your radiator, that was most likely your trouble, and when you describe the temp going over the half way mark and then dropping, seems like a T-Stat. I know you changed yours out with a NAPA part, I wonder what the difference would be in the passage ways when partially open. This could cause your temp to rise until the the T-stat is in the full open position.



My 94 2500 gasser was starting to overheat, when I checked everything but the clutch fan, that was the issue.



Did you check for the air bleed, that I mentioned in an earlier response?

 

[ichoplin]

I did put a Napa t-stat in at first. I tested the t-stat that I took out and it seemed to be working fine, so I put it back in. Who knows if the one I took out was the original one or not.

Maybe I'll go and get a new Cummins t-stat just to be sure I've covered all my bases.

Thanks,

Ian

 

[ichoplin]

another update, my truck was still running on the warm side(around 210-215deg) while unloaded. I parked it in my shop last nite and went to Tulsa to get a Cummins t-stat. When I went out there this morning to change it I found a McDonald's pancake size puddle of coolant under the water pump side of the motor. Looked underneath and saw my water pump was definitely leaking. I had already bought a new pump two weeks ago and never put it on.

So, I went ahead and put the new t-stat in when I changed the pump.

I'm driving to Chicago on Sunday and will update what I see. Should be a fair test I'd say.

Ian

 

[ichoplin]

Final update(I hope):

Drove to Chicago today from Okla. The truck ran perfectly. My temp gauge never went to the halfway mark even when passing uphill. Thanks for all the help on this one.

Ian

 

[rbattelle]

So in the end it was a combination of a bad water pump and a clogged radiator? Did the old pump look bad?

Ryan

 

[ichoplin]

Well I'm not sure if the old pump looked bad. I've seen pics of water pumps with the weep hole that went all the way through the pump. The one I took off had a hole/passageway on the bottom side that was full of crusty gunk, but it didn't go all the way through. This is where mine was leaking. The pump I put on(bought from Geno's) had the same hole/passageway. I spun the old pump and there weren't any strange noises or looseness in it. It looked as if my pump may have been leaking slowly for a little while. There was dried up coolant on the underside of the a/c compressor and around the leading edge of the oilpan. Funny how as soon as I planned on replacing the water pump, it decided to go ahead and puke a little fluid.

Ian