Need advice after overheating the *newly rebuilt* SRT4 last night :(

[CSX321]

As some of you know, I've been working for 6 months to get my SRT4 back on the road after wrecking the front end on an icy bridge in February. I'm sooo close. But last night I started it and let it idle, wanting it to get up to temp to see if I have the fans wired correctly. The high-speed fan finally kicked on, and I looked inside to see if the temp was coming down. The gauge was almost pegged! I shut it down immediately, and I put a box fan on top of the engine to cool it off.

Possible causes:

Not enough coolant and trapped air?
Bad thermostat?
Thermostat in backwards? (Is that even possible?)
Did I leave a paper towel in the pipe behind the water pump?
Bad water pump? (It's new, so that seems unlikely.)

Possible effects:

Nothing serious?
Blown head gasket?
Cracked head or block?

It was just sitting idling, so I really, really hope it didn't do serious damage. How likely is it that the head gasket went?

My plan is to drain the coolant, take out the thermostat, disconnect both hoses at the radiator, and back-flush it with water. That should tell me if I left a paper towel in there, because it should come out the lower hose. (I don't think I did, because I was worried about it right after I put the new pump in, and I used a bore scope to look up the pipe behind the pump.) Then put a new thermostat in (test it first!), and try again?

[fixit]

thoughts inline ===>

Possible causes:

Not enough coolant and trapped air?

==> bleeder valve under fill cap... did you bleed it


Bad thermostat

==> possible, throw it in a pot and bring to a boil to ensure it opens


Thermostat in backwards? (Is that even possible?)

==> not possible


Did I leave a paper towel in the pipe behind the water pump?
Bad water pump? (It's new, so that seems unlikely.)

==>unlikely, make sure to use the srt one (left) .. not a neon.. big flow difference --- http://www.srtforums.com/forums/f169/mopar-water-pump-gmb-water-pump-one-better-610733/




Nothing serious?
Blown head gasket?
Cracked head or block?

It was just sitting idling, so I really, really hope it didn't do serious damage. How likely is it that the head gasket went?

===> were the fans working, did you forget to plug them in?
===> could the head be warped allowing exhaust gas to push water out of the cooling system???
===> new head bolts right??? even better arp...?
===> all the plugs look good? oil contaminated with water?

My plan is to drain the coolant, take out the thermostat, disconnect both hoses at the radiator, and back-flush it with water. That should tell me if I left a paper towel in there, because it should come out the lower hose. (I don't think I did, because I was worried about it right after I put the new pump in, and I used a bore scope to look up the pipe behind the pump.) Then put a new thermostat in (test it first!), and try again?

[djm3452004]

Any chance you have a OBDII scanner available so you can observe real-time coolant temperature data before you begin a teardown? It would be nice to see whether the fan is kicking on at the correct temperature before doing anything too drastic.

Just a thought--

Dave

[CSX321]

Any chance you have a OBDII scanner available so you can observe real-time coolant temperature data
I do. Good idea.

[black86glhs]

How long did it idle before the temp gauge pegged? If it was only 2-3 minutes, then an air bubble is very likely. If it was for 10-15 minutes, it could still be an air bubble, but the idea makes me cringe a little.

[CSX321]

Yeah, the time from when the temp gauge first started to rise until it pegged or near pegged was maybe 2-3 minutes. Time it was pegged until I shut it off was, I think, only around 10-15 seconds. I'm feeling hopeful right now that it was just a bubble and everything is going to be fine. Maybe it's because I just drank a big Mt. Dew. :)

[cordes]

I'm guessing that you're fine. I had the coolant return from the turbo go out on me in Seattle this summer and I was surprised that I went to the arctic circle and back afterward with no ill effects. I would make sure you have enough coolant, and the system is thoroughly bled before continuing. That's probably the issue anyway.

[Force Fed Mopar]

Make sure you open the bleeder screw in the t-stat housing when you fill it.

[CSX321]

Whew! Well, it's looking good so far. There was still a lot of air in there, despite my efforts to get it out. Just about full of coolant now, and behaving normally: fans kicked on low speed just over 200 and cooled it back down.

Moving under its own power, and looking clean!
59272 59273

[contraption22]

Looks great Dave!

[cordes]

That's good news. Let is know when its all together,