Truck overheating, also spraying gear oil, need help/ideas, '02 MT

[jaymzinsa]

Hello all, I posted this in a FB R50 group and hope to get more eyes on here to take a look. I am just gonna copy/paste my FB post. 

 

This is a text message I sent to my mechanic about my truck. I put it on here to see if anyone has any thoughts/recommendations as to what might be the problem or better, come up with a solution. It seems to be almost a lost cause; sad situation because I love my beast but if I cant depend on it, I probably have to put it out to pasture. Quick synopsis, i recently completed a second build and swapped to xterra diffs with a lokka, swapped 3rd member with packed lsd, swapped out the tranny, installed a new exedy clutch, and replaced my AC system. Also had the radiator cleaned and flushed. This was to be my first real test of the recent work. The truck has never had an overheating issue before this shake down trip. Was going to go to lake havasu, about 150 miles from scottsdale, and run a bunch of trails along the lake. Had made the trip many times in the past and the truck was awesome on the trails. With the new gears the plan was to run even rougher stuff but that fell through. Please give me any feedback you feel is relevant, I want to save my buddy. Here is a synopsis of what happened.
Looks like the text makes the post too long. I will place it in the comments.

 

I took the truck out for a trip to havasu yesterday. We were very lucky to make it back. I’ll give you bullet points.
- left early morning, got to the turn off on I-10 without any issues.
- stopped to get a drink, left the truck idling as the boys were asleep and didnt want to turn off the ac, (which works great)
- got back in the truck and the temp gage is almost at overheat temp. Didnt notice until i started driving.
- once i drove for maybe 15-20s the temp immediately dropped down to normal, i literally watched the needle drop to normal temp in 1-2s. Also had a strange smell which I’ll get to later
- thought maybe stuck thermostat.
- spent the day without any issues although i did not want to take any chances and did not let the truck idle.
- left at dark and drove at 70mph 3k rpm ac on without any issues for awhile
- after ~1hr i saw the temp needle start to rise. It got to about 3/4 of the way up and i pull over at the next exit.
- waited 15-20 min, started the truck, the temp was still at 3/4 and decided to try to get to a station a couple miles up the highway to run some water on the radiator.
- as soon as i got over 15-20mph the needle immediately dropped to normal temp. Wish i had thought to take a video.
- it stayed at normal temp until the gas station. Checked the coolant reserve and it was fine. Since it was normal temp i decided to see how far we could go.
- ran for another 45min without the ac then hit a bad dust storm. Once we slowed down, the temp needle started to go up, at 3/4 temp i pulled over again.
- waited out the dust ~15min, started the truck, temp was a little more than halfway.
- as soon as we got some speed the needle again dropped to normal temp but the gearshift area and console between the seats was very hot.
- hit a huge rain storm and the drop in outside temp kept the truck temp at normal for the next 30min.
- hit construction outside phoenix and as we slowed down the needle climbed almost to overheat temp.
- i drove on the shoulder, (pissing off the stopped traffic) at 35-40mph and that dropped the temp to almost normal. Again wish i had video to show the temp needle going up and down.
- pulled into a station after getting off the highway.
- after 15-20 min drove the last 45min home with the needle staying at normal temp.
- Was a very nervous trip home but somehow we made it and in the driveway the temp was normal and the hood didnt feel hot. i let the truck idle for 5-10min to see what would happen and it ran as if everything was fine. Turned it off and there wasnt even any coolant bubbling into the overflow reservoir.
I have no idea what happened but am ready to get rid of the truck as i feel i cant trust it.
I will bring it in at some point to see if you can come up with a diagnosis. Also. At some point on the trip home, the check engine light turned off after on of our stops. Crazy.

As for the strong smell from the morning stop. There is gear oil all over the back of the truck. The pics show it even came up around the bumper and sprayed onto the liftback and rear tire mount. Gasket failure?

 

I'll try to post some pics through tapatalk to show the extent to which the gear oil was splattered over the back of the truck. I have no idea how much oil leaked, how much is left, etc. I certainly don't want to ruin the diff or cause future issues if I'm able to salvage the truck.

Any help as to the cause and/or solution for either issue is greatly appreciated.

 

Edited 20 hours ago by jaymzinsa
added pics

[RF600]

As to the possible overheating. I see you had a rad flush. I'm willing to bet you have some air in the system. Try turning on the heater and running it for a bit to circulate the coolant through the system to see if the bubble goes away. I believe there is a bleed screw on the back of the intake. There is one on the WD21's. If it's set up like the WD21, the radiator is not the highest point in the cooling system. So the bleed screw is there to get the air out.

 

I had a little air bubble in mine and it was acting weird. It would get hotter than normal and drop very little when driving. At the time it was over 100* so It wouldn't have cooled down much while driving. 

 

For the oil leak, you need to get under the vehicle and see what's leaking. If you can't tell, you would need to clean everything and then drive it to see if you can find where it's leaking.

Edited 17 hours ago by RF600

[jaymzinsa]

I considered that as I had that issue recently with my wife's mini cooper, however, we drove for 2.5 hrs straight when I left in the morning, had the AC going the whole time, ran at 3k rpm, and didnt have an issue until we stopped and I left the truck idling. Thats why im at a loss with the overheating issue, doesnt make sense. The gear oil is from the 3rd member. It is a swap from an xtrerra with 4.63 gears, a trusted knowledgable member of the forum repacked the lsd and resealed the diff before i made the swap. The gaskets werent leaking when my mechanic put it in. 

[Strato_54]

is your clutch fan dead? You can drive on the highway with the AC on with 0 fans but you really gotta be bookin' it for that. I run Efans so my driving temps are usually 174-178 (3.3 with a triple row aluminum and 170 thermostat) on the highway on a colder day and seem to like 190-200 with my fans on in traffic (gonna upgrade to T30's) so pretty cool for this engine but im also not running the clutch fan like I almost guarantee you still have. if you spin it with the engine off and it has next to 0 resistance its probably that. 

 

I don't know much about the 3.5 but don't they have an oil burning issue any ways? if your engine is getting hot and your oil starts thinning its gonna burn quicker so I wonder if you have a clutch fan issue and normal VQ issues also. just my input.

[Strato_54]

check your Diff breathers!!! I forgot that part 

[jaymzinsa]

Checked the fan clutch, its fine. Yeah 3.5VQs are notorious for burning oil as they get over 100-125k miles. I solved that issue with my first build, I swapped out a JDM engine, with 55k on it, for the original that had blown a piston at 200k. Ive put ~35k miles on it since i got it in ‘21 and change the oil every 3k miles.

 

Hadnt thought about the diff breathers. Will look into that.