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Iac / Overheating Woes - Progress And Questions

  • Thread starter Thread starter boomkat
  • Start date Start date Sep 11, 2016
  • Tags Tags
    98 mustang coolant system iac overheating thermostat
B

boomkat

Member
Sep 10, 2016
9
1
13
Sep 11, 2016
#1
  • Sep 11, 2016
  • #1
Hello all!

Progress is being made, albeit more slowly than I would like. A little backstory, though...

I traded an older truck that I had for my first Mustang - a 1998 GT with all the bolt-ons and some other miscellaneous work. The car runs and sounds fantastic. I drove the car for about 2 days and noticed some funny idling and occasional bouts of it dying due to low idle. I fixed that by replacing a lot of shoddy hoses (some were too small but had been expanded - I suspect these were leaking air) and the IAC valve. Runs like a champ now.

While I was picking up the IAC, though, I got out of the car and noticed a lot of steam coming out from under the drivers side of the hood. I also noticed a LOT of antifreeze being dumped at the front of the car on the drivers side. Once I could get the hood opened I noticed quite a bit of antifreeze on the battery and around that area, but not anywhere else.


20160908_165938

20160908_182439

I thought a hose might have busted, but all the hoses seem good. I got it home and it starts fine and runs, however, I do know the coolant is a bit low.

I was finally able to replace the thermostat, and the old o-ring was shot all to pieces. Part of it looked like it had melted to the thermostat housing, so I scraped it off and installed the new thermostat and gasket.

20160911_194853

20160911_195007

I went to refill it tonight, but for some reason the crossover plug is not in the place that I would have expected it to be based on what I am seeing online. It looks like it's right next to the alternator, but that's missing on mine. Is it common to have that moved or re-routed? I can take a better picture tomorrow when I've got more light outside.

I also noticed some brown 'mud' in the coolant reservoir. I'm betting that the coolant system just needs a good cleaning, flush, and fill. I'm going to haul it to a local shop to take care of that.

In the meantime, I'd at least like to make sure it has enough coolant (I'm not running it other than to put it on the trailer at this point). Can anyone help me locate the crossover plug or advise on alternate locations where I can find it?

Thanks in advance for helping me find this crossover plug.

- Boomkat
 
S

soupnutz

Member
May 23, 2009
73
0
6
Hampton Roads, VA
Sep 12, 2016
#2
  • Sep 12, 2016
  • #2
Crossover plug? Are you talking about the sensors on the crossover tube? A 98 should have two, one right next to the thermostat housing, and one in the same spot, but on the other side of the crossover tube. If the previous owner did a PI swap and didn't drill and tap a new hole on the t-stat side, he might have used a T-fitting and put both sensors on the other side. Pictures would help.

As for the leak, check nipple where the little hose connects to the coolant reservoir. It's up top not far from the cap. I've seen those tubes develop cracks and spew coolant out.
 
B

boomkat

Member
Sep 10, 2016
9
1
13
Sep 12, 2016
#3
  • Sep 12, 2016
  • #3
Thanks for the advice. I'll get a better picture today and check that tube while I'm at it.
 
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