the1998sr5

SO I'm still overheating. This is happening on my drive home from work. After about 20 minutes of highway driving I drive through traffic for the last leg of my journey. It does not do this everyday, but I'd say 2 out of 5 days- always at the very end of my trip. I throw the heat on and it cools back down.

New: Radiator, Thermostat, new Asin fan clutch, hoses, flush, new toyota red coolant plus water wetter, complete new exhaust, new air filter.

I just had it block tested several times hot and cold and it passed no problem. Also had it compression tested, I do not know the exact numbers, but it was good.
At 182k, did timing and water pump at 145k.

I feel like I'm running out of ideas here......
One mechanic suggested engine sludge- I'm totally skeptical on that one.
The girlfriend dose not like when I need to put the heat on (and its 90 degrees out)- I do not want to have to choose between them .

wyoming9

iTrader: (1)

Very easy choice Look her in the eyes and say it was nice knowing you .

just curious what radiator did you go with??

At any time have you been dumping coolant in??

Do you have a automatic ??

Has that ever been serviced ??

In the stop and go the small transmission cooler in the radiator is dumping lots of heat into the cooling system.

the1998sr5

I have a Koyo radiator, I forget the exact parts number, but I pulled it off this website. I bought it as soon as I got the truck to avoid the milkshake.

At times, I have felt like I may have lost an inch or two of coolant in the overflow tank.
Very minimal and over the course of months if anything. Over the last month, I have checked it religiously and it does not look to have lost a drop.

I do have my rear heater core bypassed.... The lines to the back rusted through and I did not think buying new ones made sense. I have the coolant line looped back around behind the engine. I don't expect this is a cause because it was like that for 2 years without overheating.

I do have an automatic.

I have never had the trans serviced. The trans oil is dirty, not burnt, but dirty.
I was apprehensive to service it because it shifts good and the guy I bought it from owned the car since 30k and he had no recollection of ever changing it. Again though, I never had a problem overheating and now I do- I'll buy an external cooler if you think it makes sense, but my gut asks the question " why would it be causing overheating now, but not last year?" If this was the cause.

wyoming9

iTrader: (1)

Did you drive many miles between last year and now??

The worse the transmission fluid gets the less it lubricates the less it can lubricates the hotter things get

You might even have flow problems which creates even more heat.

Simple to install a transmission temperature gauge and know for sure.

Your really not having a major coolant loss .

The whole cooling system for the most is pretty new.

My rear heater is gone as well/



Compression is good.

What else is dumping heat into the cooling system but the hot Transmission

Unless you just have so much dirt and bugs packed into the condenser

wyoming9

iTrader: (1)

Have we arrived at any conclusion just why things are getting warm??

the1998sr5

No resolution to this one yet. I've been only driving to and from work and using the heater when needed ( Which is usually just a minute or two at the end of my commute home)...

I did get a ton of responses on t4r.com as they promoted my thread to the top last week.

The leading theories are:
-timing belt slipping on water pump-perhaps tension-er was not adjusted or replaced during last timing belt change
-head gasket (i know, i know it passed the testes, but apparently an HG can be funny sometimes)
-trans oil heating the coolant

I 'm thinking I'm going to grab a B&M trans cooler and give it a shot. Guessing is painful when it hurts my pockets and I'd be reluctant to do a timing belt/water pump because I feel like I could get a used engine for 800$ and have it installed for the price shops around here are asking. If I knew for sure what the problem was, I'd fix it- but I haven't gotten there yet.

wyoming9

iTrader: (1)

Don`t know anyone with a Infra Red temp gun close to you ??

That would spot a difference in the trans cooler sand radiator coolant.

Sort of foolish to keep guessing and hope to get lucky.

Best of luck

Turtlehead

if you suspect it is the belt slipping on the water pump it could one one of two things, either the hydraulic tensioner is failing and not supplying enough tension or the water pump that was installed was a poor quality aftermarket parts and the bearing is failing. I suggest pulling the fan and covers and check the belt tension, check that their is no hydraulic oil around the piston on the tensioner and lastly see if you can turn the water pump pulley by hand with the belt on.

Another potential is that computer is getting a false reading from the temperature gauges, thus making it appear that the vehicle is over heating when in fact it may not be. As stated in the previous posts a infra red thermometer may be needed. If the thermostat that was installed was a low quality aftermarket part or is gummed up then it may too have failed prematurely.

the1998sr5

Thanks for your advice. I definitely need to get a temp gun. That said, it is certainly overheating as I see the coolant begin to boil. I would like to check the timing belt tension, but it is going to cost me. I appreciate your advice on how to check it.


Update, I was stuck in some of the worst traffic yesterday. 90 degree heat and 3 hours of stop and go because the NJ Turnpike was closed (crazy accident).


I began to overheat 40 minutes in and cranked the heat. It was miserable being that hot out with the heat on, but I must say- the temp never got above normal with the heat on. I'm not sure if I'm reading too much into this, but it seems like I just need a little extra cooling.

Would it be insane to simply route the heat outside of the car for the time being and use the heat as an auxiliary cooler? I'm getting desperate.
My logic is, the engine cant be torch-er tested more than it was yesterday and with the heat on, it did stay at normal temp.

Turtlehead

Is that new Asian fan clutch working properly? I would not route an external cooler as that is just one more place for road debris impact and corrosion to occur, and if that portion fails you are up the creek. Check that the fan clutch is working.

the1998sr5

The fan clutch is working fine as far as I can tell. Good roar on start up. Passes magazine test.

wyoming9

iTrader: (1)

You can just remove the bolts and slide the top timing belt cover out enough to look at things.

no need to remove the upper hose just loosen the clamp and slide it toward the radiator

Doing this when the engine is cold.

You have no issues with things getting warm in the winter .

I can only come up with my original idea of the transmission dumping heat into the cooling system.

Another thought just a wild guess here is where the temp gun comes into play enough passages in the radiator from new were blocked causing a reduction in cooling area.Get the wrong radiator in the correct box??

Now do not forget if your AC is on The condenser is also dumping more heat into the cooling system along with the transmission.

Turning the AC off reduces the amount of heat into the system if you think about it the heater core does not really give that much extra cooling capacity but enough to bleed off enough heat to lower temperatures to a safe level.

It comes down to not enough cooling capacity to cool things in stop and crawl traffic

Now I have the 3row copper/brass but a 5 speed and have no cooling issues with the AC on in road construction.

the1998sr5

I went out and bought a temp gun last night. Where do you suggest that I take readings? I will go out and get readings under normal operating temperature, and then I will get readings next time it gets hot as well.

Also, while I'm keeping an eye on things...What kind of reading should I get, what would be normal?

Regarding the timing bet cover. Are you saying that I can pull the cover forward without removing the fan, belts and hoses? If so I'd likely be able to it this weekend. What would I be looking for if I can get it off?

the1998sr5

The Full story on every time my truck has overheated:
2 years ago I was Wheeling and I crossed water and I broke a fan blade.
A week before this, I had crossed water that caused a misfire that went away after 10 minutes.
The engine was vibrating due to the broken fan blade and I thought it was a misfire like the week before.
I continued wheeling (moderate sand/gravel trails, normal temp).
I grossed some brush and it tore the rusty line to my rear heater.
My coolant drained and I overheated.
I filled it with river water and crimped the broken lines-got it to the trail head without getting too hot.

I did not overheat again for 7 months.
I was at a different trail in the mountains, heading up a steep (but not ridiculous) trailand I noticed it starting to get hot. I shut her down for 20 minutes, and finished the steep section- then wheeled the rest of the day on less steep sections with no overheating. Drove home an hour with no overheating.
***The caveat is that I had gone up this section before without overheating (for further clarification- it was 3 months before this episode, but still after the day the fan blade broke)
***To further complicate, when I did this trail without overheating, it may have been a much colder day with the heat on, which may make this "control" less definitive

I drove all summer and wheeled other places without over heating.
I went back to this trail in the fall and overheated in the exact same spot!!


After this, I decided not to wheel until further notice (Breaks my heart).
Which brings us to this summer and the first time I over heated when not wheeling!
I was in traffic with the AC on and I smelt coolant. Gauge was headed to the red and I got tout t check the overflow- to see it was bubbling and overflowing.

I drove for 2 weeks without the AC on and did not have a problem once.
Shortly after, I began to notice it getting hot at the end of my daily 45 minute commute- seemingly only when in traffic on hot days (after about 40 minutes of driving)

I am not sure if all of this info is relevant, but I wanted to share the full history. This covers every time I have overheated.

wyoming9

iTrader: (1)

Hot coolant enters the top of the radiator after the thermostat opens

Check the top and bottom see how much difference

pay attention to the area of the trans cooler once things are warm

It might be hotter then the coolant from the engine.

Remember that climbing hills in 4 wheel drive makes the transmission work harder

KdF

I'm gonna just throw this out here, does not mean it is for sure...but...In the "olden" days they used to put springs in the lower radiator hoses so they would not collapse from age and heat. I have noticed that I have not seen any with springs in a long time. "Could" it be that the hose is collapsing now and then to block the coolant? How long ago was it changed?

Just sayin......TM

Turtlehead

Unlikely. As stated in the original post the hoses were replaced. Even if they are aftermarket they should not be acting up at this point. Moving aftermarket parts is a different story. I like the flash back to the springs. Makes me think of better days.

the1998sr5

Thanks for your time on this guys.

The hoses are new and OEM, as is everything else I've replaced.

I've taken some temp readings on the upper and lower hose, but I have not had it overheat since I've got the temp gun.

After my drive to work today, took readings of 190 top hose, 175 bottom hose.
Yesterday during the afternoon, I drove around at lunch and got 205 top hose 185 bottom hose.

When pointed at the radiator fins I've seen a range of 165 to 145 in different spots. Higher temps seem to be on the passenger side, closer to where the top hose goes in.

At first, I thought it was crazy that I overheat only on my drive home- but now I'd guess it makes sense. In the morning my engine is cold in the beginning of my trip which is where the traffic is. On my way back I hit the traffic after my engine is already hot... And then I overheat.

wyoming9

iTrader: (1)

It only starts to get Hot afternoon after you drove normal long enough to get up to temp then get stuck in normal traffic for that time of day

Are you seeing lots of spots in the radiator that are much cooler then others if so they might be blockages

I know it will be a pain transmission pan after you get home.

Bottom line the cooling system is unable to handle the load

Why comes down to blocked passages in the radiator might even be from new.

Physical surface blocked from dirt really disrupting air being pulled in by the fan

Fan was it replaced by another stock fan I know some aftermarket fans can be installed backwards

Transmission just dumping all that heat into the cooling system

When driving right along the air under the vehicle does help cool things that could be just enough gain in heat to push it over the limit.

Don`t forget in the afternoon your also getting the heat soak from the roads as well

It all adds up.

Just where are you the Parkway Turn Pike I 80 46 10 17??

Once I get East of 287 I get combat Pay.

the1998sr5

I do this same drive every day. The needle did start to climb once in the am- but I would say about 15 times in the last 3 months between the hours of 3-6pm. Great point- I did not think about the heat soak from the road- that adds fuel to the fire as well.

The engine is not super clean. I had the valve cover gaskets replaced, but they still leak. There is a small crack where the front valve cover bolt (drivers side) was tightened too much. I zip tied one paper towel to it to prevent oil from leaking down to the alternator (which was the cause for the failing of my last alternator). I Change the paper towel every 2 weeks. I never add oil and my oil is never low- its more of a seeping.

Fan was OEM- definitely on in right direction (could not put it backwards if I wanted to).

I now live in Jersey City, which is where a lot of highways meet up, 280/rt 3/ 78/1&9.. That said, my father has a house in Bloomfield that has a driveway and a good foundation of tools (was a truck mechanic in his hay day) that I can use to work on the truck. This is exit 151 on parkway. Combat pay is no problem if we get there, I appreciate all the support thus far!

I don't mind crawling under the truck and taking a reading at the pan I'll do this tonight and report back. Heck it may even over heat today on the way home because Friday traffic is the worst, and I'll report on that as well.