Had a bit of a scare on the drive home (temporary overheating?) (1 Viewer)

[98 SNAKE EATER]

Earlier today, I was on the highway doing about 65mph on my way to pick up grandpa.

I was in the fast lane passing a slower moving van on the right when I noticed some lights rushing up behind me (some chick in an Audi)

I'm not one to be a left lane hog, so I hammered it to get out of the way and she downshifted into 3rd, but I seemed to be losing speed rather than gaining

A/C stopped blowing, which wasn't a good sign, and she slowly dropped down to about 50ish before downshifting into 2nd and held a steady speed at WOT

First thought that came to mind was HG, but I looked in the mirrors and didn't see any smoke.

Gauges all looked normal with no MIL, so I just kept my foot in it, grabbed my OBD2 Bluetooth scanner and fired up DroidScan.

No shoulder to pull over to, but I managed to make it to the next toll exit safely.

As I slowed down to a stop, the A/C kicked on again.

Looked at the temps on the screen and it was 217* and falling.

The highest I've EVER seen it go in the hottest of weather was 203*, so this wasn't good

Hit the nearest gas station and let it cool down for a few minutes as I filled the tank and checked the oil (all normal no mixing).

Started her up and the temp was down to 208*, falling fast and blowing cold A/C

It eventually settled around 195-197* and all seemed to be normal.

Drove around for about 20 minutes both locally and going WOT on the highway, but couldn't get the temps to go above 199*

I figure I probably have a sticky T-Stat, which I replaced when I installed a new radiator about 3 years ago at 251,xxx miles

https://forum.ih8mud.com/threads/question-about-radiator-leak.490973/

I'm now at 367,xxx miles and have a long distance trip at the end of the month, so I'm not taking any chances.

In the morning, I'm gunna order up a new T-stat, H2O pump (never changed before), new fan clutch (maybe a modded AJIK) and new belts.

Anyone else ever have this happen?

Open to suggestions.

 

[NLXTACY]

Hey hey hey, only one over built over heating truck at a time. Wait your turn

 

[DSRTRDR]

I recommend not reading MUD for 2 weeks - it may save your sanity

 

[rifleshooter]

You guys are freaking me out. I have a 1000 plus mile trip in two weeks! This overheating BS has got to stop.!

 

[NLXTACY]

I recommend not reading MUD for 2 weeks - it may save your sanity

I would agree!!

 

[NLXTACY]

You guys are freaking me out. I have a 1000 plus mile trip in two weeks! This overheating BS has got to stop.!

Tis the season.

 

[abrumley]

I recommend not reading MUD for 2 weeks - it may save your sanity

I second that! I'm getting way to close to getting stuck in a padded room. Joking aside replace t stat and get the ajik clutch unless you wanna mod one yourself. If it spikes again crank your rear heater to full blast and roll down the windows. It will bleed off some of the heat. Unless your stat is just stuck closed

 

[scottryana]

Might be the batman lights on your roof

 

[blkprj80]

Could a lower radiator hose collapse on one of these trucks?
Remember the hoses with big springs inside them?

If you can squeeze a hot lower hose closed with a gloved hand, it might be the problem.

 

[jakesiar]

I recommend not reading MUD for 2 weeks - it may save your sanity

My wife has actually said this to me and when I say that, I mean within the last 2 days...

 

[oilbrnr]

One curious thing about your description is the downshifting and loosing speed. Do these have the ability to go into 'limp' mode like newer vehicles do to protect themselves? Pretty sure when my HG blew I didn't loose any power... well up until it blew.

I recommend not reading MUD for 2 weeks - it may save your sanity

As well as the scanguage or equivalent!

 

[Eicca]

What you'll never know is some bird was smashed onto your grille and fell off when you decelerated.

 

[NLXTACY]

What you'll never know is some bird was smashed onto your grille and fell off when you decelerated.

Or plastic trash bag

 

[98 SNAKE EATER]

Might be the batman lights on your roof

LOL

Today was actually one of the cooler days this week, so I doubt it.

Could a lower radiator hose collapse on one of these trucks?
Remember the hoses with big springs inside them?

If you can squeeze a hot lower hose closed with a gloved hand, it might be the problem.

Didn't try the lower hose, but the top hose was fine.

One curious thing about your description is the downshifting and loosing speed. Do these have the ability to go into 'limp' mode like newer vehicles do to protect themselves? Pretty sure when my HG blew I didn't loose any power... well up until it blew.



As well as the scanguage or equivalent!

Not sure

It was definitely a scary moment though

What you'll never know is some bird was smashed onto your grille and fell off when you decelerated.

Or plastic trash bag

I actually went over the video footage thinking just that (well, trash bag at least), but didn't see anything

 

[98 SNAKE EATER]

On side note, the only thing that's out of the ordinary is an exhaust leak where the Y-pipe bolts up to the manifold (already have new seals to fix that today)

Is there anything in that area (maybe wiring or a sensor) that could've caused this due to excessive heat?

Reason I ask is that I once had a leaky muffler on my Previa that burned it's way through the O2 sensor wiring harness and would randomly short out the fuel pump circuit

It's a good distance from the T-stat and I doubt it was the MAF as it would've thrown a code

 

[98 SNAKE EATER]

Ok, a little update....

Did a fluid check earlier this morning and everything was fine (all level, no mixing)

Did a bubble test and passed (yay!!)

Fan clutch roared on start up with enough force to suck spin my auxiliary fan, then it tapered off about 15 seconds later

Hooked up my Bluetooth adapter, fired up DroidScan and headed to the shop (about a 30 minute drive)

Every thing appeared to me normal

The temps fluctuated with driving speed and never went above 203*, however, I did notice the temps were backwards compared to where they would usually be

Like at idle on the brake, it would fluctuate between 194-197* (with an intake charge temp running between 111-125*)

Around 50mph, it would stay between 197-199*

The weird part is that around 75-85mph, it would peg at 203* (with an intake charge temp running between 99-107*)

With my previous tests just a couple weeks ago, the temps would peg 203* at idle in traffic and drop down to 194-195* while moving



Anyways, I decided to order up at new T-stat, H2O pump, coolant, belts and new nuts for the fan clutch.

I'm already running an OEM Blue FC that was installed in May of 2008

https://forum.ih8mud.com/threads/pn-for-blue-fan-clutch.219149/

So I figure while I'm tearing her down for the other stuff, I'll let it drain and fill it with new fluid

 

[racer122]

Tranny wasn't slipping, right? Other than that, it seems you're addressing the logical items.

 

[98 SNAKE EATER]

Tranny is fine and fluid is still fresh.

It does take a bit of pedal to kick down when driving in "Normal" mode on the highway and I would sometimes have to hit the Power button to get her to downshift, but she's been like that from day one.

I just got back from beating beating on her for about 20 minutes and everything works as it should

 

[98 SNAKE EATER]

Well, it looks like I found the culprit

Took the Y-Pipe off to replace seal that had blown out and decided to pull the secondary cat

Sure as $h!t, it was clogged like a mofo

The primary cat on the Y-Pipe looked fine...
Didn't have another cat in stock and VatoZone wanted $365 for whatever the hell brand they wanted to order for me

So, we took a screwy driver to it and unclogged it

Not only is she quieter now because of the new Y-pipe seals, but she's got quite a boost in power now that she's free flowing

All this time I figured the lack in power was due to the high mileage

I was actually passing people on the way home today

No MIL (yet), but I've only done one drive cycle so far

Still gunna install the new T-Stat, H2O pump and modify the FC with new fluid

 

[scottryana]

Was this like 300k miles on the original cat? Yeah that clog would do it! lol