HMX-1

So I've been having cooling issues and figured I should try more than just my brain and get some out of the box thinking.

My '08 isn't cooling right. I've already flushed the coolant and replaced with new HOAT, I've replaced the radiator cap (dealer and coolant tech both said it wasn't holding at 20 pounds), and I've replaced the thermostat with a 180 degree down from the 190.

I keep seeing temps over 200 degrees (roughly 205 - 210) even if I'm not towing. While towing, I've seen it reach 220 or more degrees and then drop suddenly back down into the 180 - 190 degree range.

I don't trust my dealer since they've been known to "throw parts at problems" until it's fixed, and I can't be down that long.

Truck has a little over 61,000 miles on it and the plan is to do the EGR delete to help with temps, but this is getting to be borderline crazy.


Any thoughts on what it could be, before I take it to the dealer and watch them chuck parts at it until they get a bullseye?


Thanks!


-Kris

BigIron70

Did you check the EGR cooler ? I have changed a few for that issue, pull the EGR crossover tube and check for coolant. If it is leaking tube will be clean without any soot in it. So will the EGR valve. You can also do a block check to be sure head gasket isn't leaking. Just make sure you drain some coolant first so it doesn't get into the block check tester. Engine should be at operating temp. when testing for head gasket leakage.

madhat

I wonder if you could have an air bubble in the system...

BigIron70

Easy to check for air is to pull plug at the EGR cooler any air in cooling system will vent there.

HMX-1

Thanks guys .... looks like I have my work cut out for me this weekend.



-Kris

Green_Machine

Is your fan kicking on above 195 deg? If not, then look at the fan clutch, and the electrical connector which has a habit of corroding.

Without the fan you will overheat.

Chay

HMX-1

Update:

It needed to be burped and I still see temp spikes, but I've made sure it's full in the radiator and tank.

Runs hot when at highway speed (when I stick my foot in it) but when I stop it drops to 180 degrees. New t-stat from Cummins, 180 degree. Fan comes on when it should, but it's slow to cool.

It's deleted like Blake's thread (unplugged EGR on the exhaust side, removed plunger on the intake side) and it's running much better, except for the temps.

I'm thinking maybe the fan clutch, so is there a way to test it?



Thanks for the help.



-Kris

xcc_rider

Check frequently to see if it needs burped again. If so then you should do the head gasket leak testing.

HMX-1

How would I do this?

Crossing my fingers it's not a head gasket, but I did find the serp belt did eat up a portion of the timing cover so I'm going to need to get in there anyway.


Thanks!


-Kris

xcc_rider

There's test kits available to test your coolant at auto parts stores or a repair shop can test it for you.
Is your coolant reservoir tank filling/over flowing after it gets the temp spikes?

HMX-1

The reservoir isn't filling or emptying, and I don't smell coolant and it doesn't smell hot ... which is what makes this so odd.

I'll call around to see if I can find a coolant tester or someone that can do the test.

I'll tear into this weekend again and see what else I can find. The small hole in the timing cover has me bother, and I'm not looking forward to any other surprises.


-Kris

xcc_rider

Make sure you check the egr cooler as BI stated above. A leak there can give you a recurring gas bubble too.

HMX-1

Took the RV out to prep it for the upcoming season, and guess what?

Looks like I might have an EGR leak into the coolant.

Spooled up the turbo to take the RV down to the RV dump (I'm not dumping bleach, water, and RV anti-freeze in the street). Damned near blew the upper radiator hose off, as this is where I finally found the leak. Taking it in today to see how bad this is going to cost me


I'll update when I know more .....



-Kris

mega-engr

I guess hoping it is the EGR Cooler and not a head gasket...

madhat

Well, that's crap.