300Tdi Running a bit hot

AdamSanta85

Well-known member
FYI, All this talk of theromstat temps is funny, if you fit a 190 (88C) Stat that is the opening temp, the enginner I talked to at Stant says the fully open temp is 20 deg F higher. So at the fully open temp is when the by-pass is covered (closed) allowing full flow to the rad. Which is in the realm of the most efficient temps for a diesel. What UD said earlier.

WHEN DOES A THERMOSTAT START TO OPEN?
The thermostat starts to open at the rated temperature, plus or minus 2 degrees (F).

WHEN IS A THERMOSTAT FULLY OPEN?
The thermostat is usually fully opened at 15 - 20 degrees (F) above the opening temperature.

http://www.stant.com/index.php/english/products/consumer-products/thermostats/faqs/
 

Uncle Douglas

Well-known member
Callsign: delete
a 180 degree tstat gets you a fully open passage @ 200 which I think is where Dave's comfort zone lives, which is what I was trying to say this morning.
 

Viton

Well-known member

javelinadave

Administrator
Staff member
I'm in Arizona so 110+ is the summer norm. My concern is going up a steep hill and overheating things. If I can drop things 10 degrees as Doug said I would be in my comfort zone.
Funny thing is I just looked thru my t-stat collection and found a brand new Allmakes t-stat that the label says 88 and the t-stat is stamped 82 (180) degrees.

Why don't you check your lift pump timing first?

Lift pump or injector pump? That is the next after the t-stat but from what I'm reading it shouldn't make a big difference.
 

AdamSanta85

Well-known member
Lift pump or injector pump? That is the next after the t-stat but from what I'm reading it shouldn't make a big difference.

Oops sorry made a typo

Injection pump. Set timing to 1.54mm lift (or 1.6mm for a bit of power boost). Supposedly this will reduce your EGT, increase power, and potentially keep your water temps down.

I'll be doing mine as soon as this gasket gets here that I need for mine (200TDI needs oil filter housing removed to do it)

Do you have an EGT gauge? How are they under the conditions you are seeing the temp creep?

Sorry to be replying so much to your post but I have literally been after this same situation for months now.

<iframe width="560" height="315" src="https://www.youtube.com/embed/R6v2G0Inz5Y" frameborder="0" allowfullscreen></iframe>
 

Uncle Douglas

Well-known member
Callsign: delete
When you drive your truck on the highway does your gauge creep up?

My current 110's are Isuzu or V8 powered. Have owned tdi 110's where I could run 75 mph pulling a trailer and temps were steady around 200 on a 90 degree day. Truck didn't have a/c though. A hot a/c condenser in front of your radiator changes the equation.
I have the shaft micrometer pictured but have evolved to doing it by ear and seat of the pants, faster and easier.
 

javelinadave

Administrator
Staff member
Sorry to be replying so much to your post but I have literally been after this same situation for months now.

All good! I have an EGT gauge and there is no variable that changes the basic operating temp. Higher EGT, higher OAT make it climb a bit but it is just to warm for my liking.
 
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AdamSanta85

Well-known member
I ended up taking off from work today. I decided to try to tackle these jobs. Right now I am half way through the coolant flush. Just finished running the oxalic acid, once it cools down I will drain it and run the washing soda through. Some crap definitely came out, little brown specs floating around.

My oil filter housing gasket came too. I think I am going to try and do the injection pump timing before I put it back together since I have the hood off and the coolant hose can be out of the way. So if it fixes my issue I wont know which solved it.

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110user

Well-known member
Setting lift is critical to a Tdi preforming. You'll be happy you did it.

I think EGT's are important to monitor especially in an engine where the fuel could have been turned up.

Every time I've had a warm Tdi it has been from loss of cooling system pressure (bad overflow tank), over fueling (high EGT) or having things block the radiator (lights).

Recently I added a used ARB bumper that came with lights to my Tdi Disco, it has never ever run hot. First run on the freeway up a big hill and the temp started to creep. I took the lights off and it is back to normal... just food for thought.
 

rovercolorado

Well-known member
Setting lift is critical to a Tdi preforming. You'll be happy you did it.

I think EGT's are important to monitor especially in an engine where the fuel could have been turned up.

Every time I've had a warm Tdi it has been from loss of cooling system pressure (bad overflow tank), over fueling (high EGT) or having things block the radiator (lights).

Recently I added a used ARB bumper that came with lights to my Tdi Disco, it has never ever run hot. First run on the freeway up a big hill and the temp started to creep. I took the lights off and it is back to normal... just food for thought.
That made me think of my old Disco. I added a ARB and big lights and made a big road trip to Moab. It got really hot and when wheeling I had to open the hood to let more air in. After I returned home I got a great deal on a Saudi grill and never had the problem again after many trips to Moab.
 

jymmiejamz

Founding Member
Callsign: KN4JHI
No difference with the 14 gauge wire.
Guess a 180 degree t-stat is the next step.

Currently 85 degrees out on the test drive.

What's wrong with that?

FYI, All this talk of theromstat temps is funny, if you fit a 190 (88C) Stat that is the opening temp, the enginner I talked to at Stant says the fully open temp is 20 deg F higher. So at the fully open temp is when the by-pass is covered (closed) allowing full flow to the rad. Which is in the realm of the most efficient temps for a diesel. What UD said earlier.

I may be wrong, but I thought thermostat ratings can vary by brand. I always thought a Genuine RV8 thermostat was fully open at 88C.

Why don't you check your lift pump timing first?
--------

I don't get how many "experts" of these trucks claim they are over cooled and don't need a fan this and that. So many claim there trucks run 189 and the gauge never budges. Yet here you are with a big ass aftermarket rad and fan and have a creeping gauge.

I didn't run a fan on my 300 Tdi 110 and never had it run even a little bit warm. The fan is only for low speeds, and diesels don't generate a lot of heat at low engine speed/load.


I don't like watching my water temp gauge creep up and down.

Then you need to buy a newer vehicle or install some sort of signal conditioner for the temp gauge. The temperature of an engine is always changing, but modern vehicles do not have gauges that move.
 

javelinadave

Administrator
Staff member
Success!
182 without the A/C driving up hill.
190 with A/C driving up hill.
Instantly back to 182 headed downhill.
 

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javelinadave

Administrator
Staff member
Ok. I advanced the timing a bit. I drive up the steepest grade in AZ and it was 100 degrees outside. 199 on the gauge with a/c running. I think I'm good.
 
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