Jump to content

Recommended Posts

I feel like my Jeep won't get up to temp. I posted elsewhere and was told it was nothing to be concerned about..

 

So per an IR thermometer at the t-stat housing, the coolant will get up to 170-175 degrees after 20-30 mins of mixed driving.

-The heat works great and both heater hoses are hot.

-The upper radiator hose gets warm-hot.

-The radiator is reading 100-130 degrees via IR thermometer. The radiator cap does not get hot. It was 43 degrees out when I did this drive.

 

88 Comanche with open cooling system, 4.0l. 

 

Flushed the (already pretty clean and under 2yr old) cooling system 2 times, once with VC9 and the other dish detergent, with no heater core in the loop. Then replaced heater core, and put in a new 195 degree Stant thermostat. Coolant is roughly a 50-50 mix and all new. I did all this and now it won't get up to temp. Before this the Jeep always ran perfectly at 205/210 and never had an overheating issue.

 

Any ideas?

Link to comment
Share on other sites

- Most likely cause is using a tstat that is not 195*  these commonly come faulty out of the box, it's best to buy 2-3 at a time. 

- The next likely cause is a pressure leak in the coolant system.  This usually is at the radiator cap.  

If those don't fix it, grab you rad hoses with the engine running and make sure you have water flow.  If you are getting flow and nothing else seems to be wrong, I don't know what it could be.  Do you have any upgraded cooling parts? 

Link to comment
Share on other sites

1 minute ago, Dzimm said:

grab you rad hoses with the engine running and make sure you have water flow. 

...

Do you have any upgraded cooling parts? 

If there is no flow, what would you suggest from that point? I'll check tomorrow. I'm feeling heat in all my hoses, so I assume there is flow based on that. Not just the general engine bay warmth kind of heat.

 

No real upgrades in the performance sense. I switched to Open cooling using the Spectra radiator, and got a newer style t-stat housing so I could put a temp sensor for my stand-alone electric fan controller, which just controls a 2000 xj oem efan around 220. Otherwise, it's all factory equivalent parts.

Link to comment
Share on other sites

1 minute ago, MichiganDuck2 said:

If there is no flow, what would you suggest from that point? I'll check tomorrow. I'm feeling heat in all my hoses, so I assume there is flow based on that. Not just the general engine bay warmth kind of heat.

 

No real upgrades in the performance sense. I switched to Open cooling using the Spectra radiator, and got a newer style t-stat housing so I could put a temp sensor for my stand-alone electric fan controller, which just controls a 2000 xj oem efan around 220. Otherwise, it's all factory equivalent parts.

If you have no flow or slow flow, you probably have air in the system.  That's still a possibility if there is flow.  Otherwise it could be a bad or stuck water pump or a clog somewhere in the cooling system.  

 

First thing I'd try, park the truck facing up a slope to get the radiator higher than the engine, open the radiator up with the engine running(make sure its still cold!) Burp any air out you can with the truck like this. 

 

My best guess is a bad tstat but it could also be a bad rad cap.  These are cheap and good to have extras on hand but try burping air before spending money.   

Link to comment
Share on other sites

2 hours ago, gogmorgo said:

Wouldn't low coolant flow cause overheating, not the OP's, um, underheating?

9 time out of 10 yes, however I've had it do the opposite on my 98 xj.  Flushed the sludge out of the cooling system and it was fine after that.  The only thing I could gather was that the coolant wasn't getting to the temp sensor. :dunno: 

Link to comment
Share on other sites

1 hour ago, omega_rugal said:

any problems running cold? bad MPGs? lack of power?

You could potentially see those things.  Really it's more wear on the engine and trans because they aren't running at the Temps they were designed to.  Colder is better but too cold isn't.  But then again, how cold is too cold? 

Link to comment
Share on other sites

15 hours ago, MichiganDuck2 said:

I did all this and now it won't get up to temp. Before this the Jeep always ran perfectly at 205/210 and never had an overheating issue.

 

I get all mixed up unless things are real simple. Too hot?? Too cold?? Which one?

Link to comment
Share on other sites

33 minutes ago, Ωhm said:

 

I get all mixed up unless things are real simple. Too hot?? Too cold?? Which one?

 Sorry about that, I was trying to say that prior it always ran at the proper temps and never got too warm which is the usual problem with our old Jeeps.

 

However, my current problem is that it is too cold.

3 hours ago, cruiser54 said:

Get a 52028186 factory stat and be done with it. 

I will do this and report back.

Link to comment
Share on other sites

I've never had real issues with Stant tstats but I've taken to testing them on the stove before installing them.  Also, they have two lines of them, an economy and a OE replacement, but I don't think they actually have anything indicating such on the box, they're just different P/Ns.

 

If it's running cold start with the tstat.

 

 

Link to comment
Share on other sites

I've never had any luck with a Stant, both I tried made my 4.0 run at 160F.

Went back to my old go to thermostat ... The old Motorad Failsafe (195F).

Current one is doing it's fourth year (and now second motor), holds 198F in the dead of winter here, and now runs at a steady 203F since I blocked three grill vents for the cold snaps since I was getting slower warmup times this winter. Probably a sign I need to do the pump (pull and inspect/replace and thermostat again this spring. Summer Temps were the same range (but I didn't have an REM to get a more accurate value).

Sent from my SM-G930W8 using Tapatalk

Link to comment
Share on other sites

Motorad 195 in mine as well, sits at 210 and heats up nicely even at -40 with completely open grill. I just wish I could heat up the diffs a bit so it doesn't feel like it's driving through glue for the first few minutes...

Link to comment
Share on other sites

Depends. If I let it idle until the coolants's at operating temperature it does okay, maybe it's a little slower to shift but nothing catastrophic. If I don't give it the warm up though it really hangs between gears long enough the engine will rev up then it'll slam into gear with the extra pressure for the first dozen or so shifts or couple minutes of driving.

The heat transfer from the coolant in the radiator is definitely noticeable below ~0°F, to the point of critical when the temperature really takes a dive, which I'm guessing is what you're wondering about. The block heater also makes a fair bit of difference in shifting... the hardest shifting was definitely on those mornings when I discovered that the breaker for my exterior outlet blew so the block heater wasn't getting power. Which is totally awesome when you're like me and tend to roll out of bed maybe 15 minutes before you need to leave for work and don't realize until you get that painfully slow crank when you hit the key.

Link to comment
Share on other sites

Thanks. I've recently bypassed my radiator tranny cooler and added another external tranny cooler, and was curious how your AW4 did in that extreme cold. It's very rare when the temps get to 0*F here; the lower teens is about as cold as it ever gets. And that's not often. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...