Lights on front affect cooling?

Classic4X4

Well-known member
Might have just figured this out! Check out this photo, these guys were dangling next to a bolt coming out of the firewall. Just popped them on and my fuel gauge works. My God... I'll take a quick drive and see what happens. Damn contacts were hiding back there. I scowered the entire engine bay for these things..
 

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Classic4X4

Well-known member
Hmm OK feel a bit guilty but at least we know it isn't the t-stat.

Some thoughts:

Is the truck so under fueled that it can't get the engine hot? Is that even possible? Maybe the truck is getting warm but the gauge is reading inaccurate?

Where is the gauge grounded?

The temp gauge in particular is very sensitive to ground. I ended up having to ground my gauge independently on the fire wall AND run a little ground strap from cylinder head to firewall.

What temp probe do you have? VDO? Part number 323-422

Are you using the original temp sender wire or a new one? What gauge wire?

Is there teflon tape on the probe? I also had that as problem because I didn't read the instructions.

It looks like the probe is VDO 323-422, I can pull it out and take a look to see if there's any teflon tape. In terms of grounding of the gauge, I think the wiring harness that comes with the usual kit is spliced into 3 so one main ground wire contact which I think I connected (fuel gauge working). I'm not sure if the wire is original or not. It looks like a newer part
 

AdamSanta85

Well-known member
It looks like the probe is VDO 323-422, I can pull it out and take a look to see if there's any teflon tape. In terms of grounding of the gauge, I think the wiring harness that comes with the usual kit is spliced into 3 so one main ground wire contact which I think I connected (fuel gauge working). I'm not sure if the wire is original or not. It looks like a newer part

Ok you might want to try what I did. The temp gauge instructions specifically requests an independent ground. Ground the gauge to the fire wall by itself with a 14ish gauge wire. The probe is grounded to the cylinder head via the probe threads (hence why teflon will mess it up). Then get a ground strap from Autozone or whatever and run it from cylinder head to firewall. This will have positive benefits regardless if it solves the problem, and we can continue to check off things it can't be.

Something like this for ground strap
https://www.autozone.com/gaskets-an...d-strap/help-universal-ground-strap/98830_0_0

Additionally and probably even first, get a cheap IR temp gun from like Harbor Freight. You can get them for free sometimes with their coupons (how I got mine). That will tell you for sure if its gauge reading low or not

https://www.harborfreight.com/Non-Contact-Infrared-Thermometer-With-Laser-Targeting-69465.html
 

Red90

Well-known member
Like I said earlier.

1) Post a picture of the front of the engine to show the cooling hoses and such to make sure it is assembled properly.

2) Measure the engine temperature to determine if it is the gauge or the cooling system.

Once we know that, then spend effort fixing the problem.
 

Red90

Well-known member
Oops, missed that post. Well is that not pretty. Someone spent a lot of money with that install.

Looks like there is a new wire for the coolant sender, so I would guess it runs straight to the gauge. See if you can follow that and make sure that is the case. If there are any intermediate connectors, look them over. A dedicated wire is the safest.

Check the engine ground strap. I imagine it runs close to the exhaust downpipe.
 

Classic4X4

Well-known member
Just picked up an IR gun from auto zone. Took a few pictures of engine bay readings


1 manifold

2 passenger side engine block

3 right above Tstat

4 drivers side block
 

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Red90

Well-known member
So. It looks like it is the gauge then. Either the sender wire or the ground path. Make sure there is a ground strap from the block to the frame and it is secure. Adding one to the bulkhead as Adam suggests is a good idea as well.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
Curious if this was resolved for you. A lot of what you are dealing with sounds like my truck. I can get temps up to 180+, but only after a good 1/2 hour, or a hill climb at 60mph or so.

I think your tach must be set too low. I can't imagine getting the turbo to spin much at all at 2000 rpm, and I can hear it in your video.

My truck will do 60, and 65, but it does not like to go 70. The RPMs I see are just about 100 too high as compared to the charts you can get from Ashcroft, so I know that my tach is set a bit high, and I can compensate as I look at it. I know that the fueling is good, I can't see that there is anything wrong with the throttle cable, but my EGTs are very slow to react. It takes 10 minutes to drop from 650 to 450 when at idle. And on a good hill at 50-60mph it will take over a minute to get to 950+. I have never seen it go over 1250, even on a hill, 5th gear, 55mph, floored.
 

LazyRabbit

Well-known member
Curious if this was resolved for you. A lot of what you are dealing with sounds like my truck. I can get temps up to 180+, but only after a good 1/2 hour, or a hill climb at 60mph or so.

I think your tach must be set too low. I can't imagine getting the turbo to spin much at all at 2000 rpm, and I can hear it in your video.

My truck will do 60, and 65, but it does not like to go 70. The RPMs I see are just about 100 too high as compared to the charts you can get from Ashcroft, so I know that my tach is set a bit high, and I can compensate as I look at it. I know that the fueling is good, I can't see that there is anything wrong with the throttle cable, but my EGTs are very slow to react. It takes 10 minutes to drop from 650 to 450 when at idle. And on a good hill at 50-60mph it will take over a minute to get to 950+. I have never seen it go over 1250, even on a hill, 5th gear, 55mph, floored.

Sounds like my truck, i just don't have an egt monitor. For me, i think the water pump is on it's way out and it cant push the volume that is needed. Everything is in the cooling seems spot on.and my engine isn't over tuned, it might even be de-tuned. On hills or even sometimes doing 60 plus, i'll just watch the thermostat needle keep creeping up until i pull off and let it sit for a while. I even try the electric van with viscous van on up hills and still heats up.
 

mgreenspan

Founding Member
Make sure your radiator is not clogged and has proper flow. What you guys are describing sounds like poor flow thru a radiator to me. It's not completely blocked but enough that under increased load it can't cope. I drove my converted 200tdi 90 with stock rad and intercooler all over Scotland at various speed ranges and never had to worry about anything like this and never ran an egt gauge. And don't trust "new" as guaranteed good flow.

The water pump could be the issue but don't these weep when they are dying?
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
I’ve never seen mine go above 220. That’s sitting still with no fan after a hill climb on a 90 degree day.
 

Napalm00

Technical Excellence Contributor
To answer the original question of this thread lights on the front will definitely affect Cooling.


200 300tdi inherently will run cool. I ran my truck for a full year without even a fan on it... My electric fan controller had died and I didn't even notice.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
To answer the original question of this thread lights on the front will definitely affect Cooling.

200 300tdi inherently will run cool. I ran my truck for a full year without even a fan on it... My electric fan controller had died and I didn't even notice.

I have purposefully left a fan off of mine. That is, no viscous fan. I have an electric that so far I've only used once while driving in heavy traffic on blacktop at 85 degrees; I have turned it two or three times after coming home on hot days. It is 1/2 mile and 800 foot climb to my driveway, so I almost always sit and wait for the EGTs to come down, and I sometimes see the water temp go up after that hill climb on a warm day.

I am about to put a radiator cover on for the winter. My engine is just barely too hot to touch by the time I finish my daily commute, even if it is 70 degrees outside.
 

Napalm00

Technical Excellence Contributor
Thats pretty normal, mine won't get hot unless driven at 65-70 for about an hour.

They run cool
 

Classic4X4

Well-known member
Never ended up resolving this. I have no problem with cooling. Brand new Ali-Sport aluminum radiator/intercooler does the job, Now, my fan relay did finally die on me a while ago on the trails and I overheated (easy fix). The gauge (water temp) did show an increase in heat but when Im driving on the road regularly it just sits right at about 100. Kind of accepted it and at a total loss of what to do.
 
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