I have a 1999 suburban 6.5 , truk is running to cold I replaced the thermostst but didnt help any IDEA?

any one have diagram on how to instal thermostst on Suburban 1999, ther are two thermostat I need to know how they should sit in the housing

The "pointy" end of the thermostat faces towards the back of the truck, both are installed the same way.

How did yo go about filling it? did you bring the engine up to temp so that you could top it off after the t stats open? Have you added any after it was started

my question is how cold is the climate where you are, the sub in my sig normally runs 170-180*F but with the deep freeze we got this last week it was running down at 160*F till we put some card board blocking most of the grill opening. same with the dodge except it normally runs 190*F and was running at 150-160*F with the -5*F temp out side. now my 95 normally runs 210* and was running at 190* in the cold with no cardboard blocking the grill. so if its really cold where you are the thermostat may not make a diffrence.

Justin

in Ontario Canada for few days it was cold -30 but now is about -14. I replaced the thermostat for the second time and I install them as CHEVYINLINESIX said but still running a bit cold in Hway it goes up to 76C max, so it dosent even have enough heat for heater. I fill the coolant after running the car for about 30 minutes, thermostat som- how opened and I fill the reserve tank, I drove for about 65 km or 40 Miles but when I got home reserve tank was just warm. I don't know what to do any more. It is cold in here can't drive with out heat I also have the heating core replaced two months ago.

Did you use the AC Delco thermostats? Expensive but recommended.

yes I did use AC Delco thermostat

Do they look like the one on the left in the picture? And what is the temp. eg 195*

no they don't look like that the back part is black and and I didnt se the 195 on it or any number

Not so much the color, the shape should look like the one on the left.

jkhnanishoo (http://www.dieselplace.com/forum/member.php?u=95368),

I could not get heat out of my Van when I went to CO a couple weeks ago. So I put cardboard over the front of my radiator to block any air from coming into contact with the front. I did not put cardboard on the truck grill, I put it between the oil cooler and the radiator... touching the radiator core. I covered 100% of radiator when driving on flat ground and had to uncover about 25-50% when climbing long grades.

Keep and eye on the water temp and adjust the amount of covering to get the temp you want.

hope this helps,

Dale

Ooh, one other thing. I discovered that advancing the IP timing will also help to create engine (water) heat. Not sure exactly why this is the case, but I just advanced my IP and the temp is now much higher.

Not so much the color, the shape should look like the one on the left.

mine look different I bout it from GM dealer

If they don't look like the one on the left, you may have found your problem. The dealer might have given you ones for a gasser, did the ones you originally took out look like the one on the left or right?

Dug out my bill for AC Delco thermostat part #12559338 $39.95

If they don't look like the one on the left, you may have found your problem. The dealer might have given you ones for a gasser, did the ones you originally took out look like the one on the left or right?

no the one I tooke out was exactly like the one I bout, as I told you I bought 4 thermostat at two different time in 4 days and I told them car is deisel, thats why the second time deler part salesman recoment to put two other new one just in case one was defective

Do you have another GM dealer close by? If so, try them, the other dealer maybe confused if they just matched them to the old ones.

Do you have another GM dealer close by? If so, try them, the other dealer maybe confused if they just matched them to the old ones.

yes I will try that i the morning

If they don't look like the one on the left, you may have found your problem. The dealer might have given you ones for a gasser, did the ones you originally took out look like the one on the left or right?

Dug out my bill for AC Delco thermostat part #12559338 $39.95
That gm part number will not fit his truck it is a 99 with dual t stats. Now they are the same as the gasser.

yes I will try that i the morning

thanks for your time anyway

jkhnanishoo (http://www.dieselplace.com/forum/member.php?u=95368),

I could not get heat out of my Van when I went to CO a couple weeks ago. So I put cardboard over the front of my radiator to block any air from coming into contact with the front. I did not put cardboard on the truck grill, I put it between the oil cooler and the radiator... touching the radiator core. I covered 100% of radiator when driving on flat ground and had to uncover about 25-50% when climbing long grades.

Keep and eye on the water temp and adjust the amount of covering to get the temp you want.

hope this helps,

Dale

thanks for the advise tomarrow I will try the cardboard hopfully it will work

That gm part number will not fit his truck it is a 99 with dual t stats. Now they are the same as the gasser.

may be and they seat in the same housing

yes your truck shouldnt take any thing odd. Other then haveing 2.
Just a question how much water did you use with the coolant?

yes your truck shouldnt take any thing odd. Other then haveing 2.
Just a question how much water did you use with the coolant?

I put 50/50 water mixed

So your engine will not get up to temp.

I wish it would, why? are'nt you supose to add water in 100% coolent?

you must have water with the coolant

So your engine will not get up to temp.

How did you fill it? Did you full then start it and keep adding till the upper hose was to hot to hold?

Sorry mine is a single 95 model, wasn't aware they were different. You should not need cardboard on the rad if everything is working proper. Ever see a new vehicle from the factory with cardboard on the rad? You may have a plugged heater core which would give no heat, but still doesn't explain the low temp gauge reading. Keep looking and let us know.

I should have the fan clutch checked too , I wounder if that could be the problem. I fan runs on full gear

Cardboard is a patch until root problem is fixed.

And I do see a lot of Diesel trucks running around with vinyl or fabric covering their radiator intake... just look in the oncoming lane.

the t stat should get to temp. In the 60s they used solid fans and had heat. the clutch is for better mpgs.

Cardboard is a patch until root problem is fixed.

And I do see a lot of Diesel trucks running around with vinyl or fabric covering their radiator intake... just look in the oncoming lane.
Or ice road truckers.





What is the temp where you are?

the t stat should get to temp. In the 60s they used solid fans and had heat. the clutch is for better mpgs.

thats true too, Im just running out of ideas

Are you sure that it is FULL

for the last 5 days anywear from -10 to -35c

can you upload a pic of a t stat that you have taken out?

I will posted tomarrow is in the truck and in hear now is 11.30 PM

hold on 1 min.

I bet yours looks like the second one the way it sits the top should go to the hose.

I bet yours looks like the second one the way it sits the top should go to the hose.

Maybe you could give him the correct part # and see if that is what the dealer gave him.

Results 1-8 of 8
Product Part No.

Duralast / Thermostat 4399
Note:
195 degrees
Original equipment temperature 2 required. Seal included.
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Cst/valucraft / Thermostat 4399
Note:
195 degrees
Original equipment temperature, seal included - 2 required
Enter ZIP code above to check availability and pricing

Failsafe / Thermostat 7200-195
Note:
195 degrees
Original equipment temperature. Designed to lock open at approximately 280 °F to provide maximum coolant flow during overheating condition.
Enter ZIP code above to check availability and pricing

Failsafe / Thermostat 7200-180
Note:
180 degrees
Designed to lock open at approximately 280 °F to provide maximum coolant flow during overheating condition.
Enter ZIP code above to check availability and pricing

Failsafe / Thermostat 7200-160
Note:
160 degrees
Designed to lock open at approximately 280 °F to provide maximum coolant flow during overheating condition.
Enter ZIP code above to check availability and pricing

Duralast / Thermostat 15356BP
Note:
Low temp-160 degree
Enter ZIP code above to check availability and pricing

Duralast / Thermostat 15358BP
Note:
Med temp-180 degree
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Duralast / Thermostat 15359BP
Note:
High temp-195 degree
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Repair Information for your:
1999 Chevrolet Truck K2500 3/4ton Sub 4WD 6.5L Turbo Diesel
Vehicle Repair Guides:
Escalade, Suburban, Tahoe, Yukon, Denali, Denali XL, Yukon XL, 1999 – 2005

Duralast
Brands:
Duralast
Failsafe
Cst/valucraft
Related Parts
Thermostat Gasket
Water Outlet
Hose (Upper)
Hose (Lower)
Hose (Heater)
Radiator Cap
Manual - Vehicle Maintenance


This is an auto zone online shoping site. And I Dont have a oe number.

For Dual Thermostat (96-99): ACDelco #:131103 GM#:12559336

190 Degrees

Source: RockAuto.

jkhnanishoo, I would bet if you used something to cover up the grill with the temps that you are getting it would show if you have fixed your problem. this is the reason why companies make "winter fronts" for diesel trucks. Semi's or pickups it dosnt matter. Your diesel engine relies on heat to make combustion if your ambeiant tempature is so cold that your motor cant keep heat in it with the cold blowing in on the rad and motor then you need something to block the cold air from coming in the front of the truck. If you block the grill, then your fan still is able to draw air through all of the coolers. And it isnt the frigid air that is directly blowing in on its own any time your drive. Our 6.5td engines as well as most other diesels dont make enough heat at idle to maintain temp inside the combustion chamber which is why people add a high idle.

So if you block off the wind from the rad then you will see if your t-stats are good or not. If your motor gets up to temp and then the t-stats continue to regulate the proper temp then every thing is working as it should, it is just to cold out side for the motor to keep up with the heat loss from the frigid tempatures you are having. If one of your t-stats is junk and stuck open then blocking the grill wolnt help much if at all. So I say try it. My trucks temp normally runs high "210*F" and with it being -5*F it pulled the temp down to 185*F. So if your truck has a normal running temp then the cold your having would drag the temp down to a point where you would get very little heat in the motor. I used to live in Wisconsin and I have seen it where it was -40*F cars (gas and diesel)dont warm up at that temp unless you have the grill blocked. ok enough thats my $.02

Justin

Some things I checked when mine was overcooling:
1. Made sure coolant was full and all air in system bled off
2. Made sure fan clutch was not hard to turn (I could turn it with one finger)
3. Felt the temperature of upper radiator hose while engine is at operating temperature, it should be hot, but not so hot that you can't touch it.
4. With engine off and key on, unplug temperature gauge sensor, it should make the gauge on your dashboard read either all the way hot or all the way cold (can't remember)
5. With engine off and key on, run a jumper wire from the wire for the temperature gauge to a good engine ground, and the gauge should read either all the way hot or all the way cold (can't remember which way it goes)
6. If when you do check 4 & 5 the gauge responds correctly, then the temperature sensor is bad. However, if it does not respond as it should, you have a bad wire going to the gauge or a bad gauge.
7. Low ambient temperature, combined with light engine load (idling) it will not reach full operating temperature (at least mine wouldn't)
8. Make sure the rubber gaskets on the thermostats are on, and that you did not substitute them for RTV sealant on the housing. (I almost did this)
9. Make sure the bypass hose is not plugged, as it will cause excessive pressure behind the thermostats and force them open.
10. Somebody finish me off here...and no pun intended!
NOTE: In lost without sparkplugs' post, my thermostats look like the first picture. My diesel thermostats look the exact same as my high flow thermostat for my 383 stroker except for the rubber gasket.

I bet yours looks like the second one the way it sits the top should go to the hose.

the picture on the left is the one I have. I put a cardboard on the grill , today outside is -25 in Toronto, I drove in Hway and temperature deading was about 80C better than 72C.

Mine is lucky to run at 80 degrees Celcius at highway, or even town driving.

I had made a grille blockoff for the truck, but then it started stalling, blah blah blah, typical pmd issues.

Took the grille block off off.... Issues are gone.

Mind you, I still have a PMD, I'll be ordering heaths relocate kit before the summer though.

Just an FYI, not sure if you have a PMD still or not.

Also, I noticed, Blueburby's truck runs a bit hotter then mine, we just attributed that to his being heavier, thus the engine works harder.

Although, when I'm on it hard, and either playin, or haulin ass up hill, the highest I'll get it is almost 100C, but it'll cool right back down, so I just figured I had good cooling.

I am having the exact same problems, I did notice my heater core is some what plugged, but even with cardboard I have to do 120k on the highway to make 85c. I am going to try a new heater core this week. Does anyone know of instructions for changing the heater core?

If you chenge it could you please let me know if your problem is fixed .Thnks
I bleave you need to take the intier dash out, top and the bottom be ready for 5 to 6 hours of work .I wish I had fule instruction , but if you could get a diagram if the location for heating cor from one of the part supplies store it will be a big help. I had done it but a michanic was cheking on my work and telling me what to do. good luck

All I can see is this in the manual:

REMOVAL & INSTALLATION
BLOWER MOTOR
Removal & Installation ("C" & "K" Series - Pickup, Escalade, Sierra, Suburban, Tahoe & Yukon)
1. Disconnect negative battery cable. Remove glove box. Remove front screw from right door sill plate.
Remove passenger's kick panel. Unplug connector from Electronic Control Module (ECM) if necessary.
Unplug connector from blower motor. Remove blower motor cover and cooling tube.
2. Remove bolt from right instrument panel pivot support. Remove blower motor flange screws. Pull blower
motor forward carefully to avoid distorting blower fan. Remove blower motor. To install, reverse removal
procedure.

HEATER CORE
Removal & Installation ("C" & "K" Series)
1. Disable air bag system. See AIR BAG SYSTEM SAFETY article in GENERAL INFORMATION.
Disconnect negative battery cable. Remove glove box by squeezing sides together. Remove 2 instrument
panel retaining bolts from glove box opening. Remove center floor duct. Remove center support bolt.
Remove Electronic Control Module (ECM) and tray. Remove both kick panels. Remove blower motor
cover and blower motor.
2. Remove driver's lower instrument panel cover and knee bolster. Lower steering column. Remove
instrument panel left and right pivot bolts located at lower corners of instrument panel. Remove 3 screws
from defrost vent, near windshield. Disconnect any connectors and tilt instrument panel back far enough
to access heater case. Remove coolant recovery reservoir from engine compartment. Drain engine
coolant. Disconnect heater hoses at core. Remove bolts and nuts from engine compartment attaching
heater case to vehicle. Remove heater case.
3. Remove 7 screws attaching heater case cover plate. Remove screws and bracket attaching core to case.
See Fig. 6 . Remove heater core. To install, reverse removal procedure. Replace any seals. Fill cooling
system. Start engine and check for leaks.
CAUTION: Heater core can be damaged if too much force is applied to heater core
pipes during hose removal.
NOTE: On "C" and "K" series, heater core may be accessible without removing heater
case. Remove passenger's side door sill plate and kick panel. Pull passenger's
side of carpet back enough to access bolt at rear of heater case cover plate. If
all heater case cover plate screws are accessible, begin procedure at step 3).
1999 GMC Pickup K2500
1999 HEATER SYSTEMS RWD Trucks & Vans - Except Tracker

Wow, changed the stats again and replaced the heater core. I HAVE HOT HOT HEAT!!!! To change the heater core I just pealed back the carpet and removed all the screws out of the bottom of the plenium. Drained the rad and disconnected the two hoses to the heater core. The only problem I had was it was impossible to get the clamps off the hoses going into the heater core. because it looks like they were installed with the exhaust removed so my pliers would not fit. My buddy got me these amazing pliers called Flexible Hose Clamp Pliers. I could not have done the job without them,


http://www.toolfetch.com/media/101225.jpg

You do not need to remove the computer or the blower to do this job. It is -12c and my truck was hot within minutes.

you want to come do mine, i get some heat but its not all that warm, i have 3 heater cores laying around here, i just am dreading trying to install it. :D

It was quite some years ago and I can't recall the details, but I had the same problem on mine.

It turned out to be a small piece of plastic that had broken off somewhere in the cooling system. It was lodged in such a way as to act like a restrictor in the cooling system. It would allow enough water to circulate for mild heat on not too cold days.

I'm not sure, but I think it was close to the thermostat housing. You had to look real hard to see it. It was such that it looked like it belonged where it was.

Harbor Freight sells a cheap infrared thermometer. It can come in handy for checking things such as your problem out.
Take readings at different locations and along hoses to see if the temps. are what you expect in that area.

you want to come do mine, i get some heat but its not all that warm, i have 3 heater cores laying around here, i just am dreading trying to install it. :D

It wasn't as bad as I thought although I could not get rad drain open and even if I did, it looks like it is a stupid location.