Temp guage problem

[TDI Guy]

After driving in all the rain at MAR, i noticed my temp guage was all over the place and jumping from 180 up to 220 and back. what could cause this? Also, when I turned on the lights it would make the guage read even higher. I don't think the engige was running hot at all. what do you guys think i should check first?


Randy

by the way, running a 300tdi and a new VDO temp guage and sender..

[Mike Hippert]

the ground for the lights and gauge is funky, mine does the same thing when I turn on the headlights. Once it clears up and stops raining I plan on figuring it out :)

[Hans]

I've had some funky gauge issues too lately.... flipping the heat/defrost levers on the left side of the dash were turning my tach on and off for a while. Occasionally it reads really wacky, all started when I put in my Autometer temp gauge, so it's almost definitely my own damned fault.

-Hans

[TDI Guy]

I was paranoid the whole time at MAR because i thought the TDI was overheating. IT was showing 210 deg. I don't think it is posible. THen on the way home it was going from 190 to 210 in 5 seconds. I don't think that is possible. Do you guyus think its a ground or something?

[Mike Hippert]

210 isn't that hot, nto enough for me to worry my engine runs upto 195 for normal opperating and I don't worry until I see 220 and up 230, 240 is bad. But if the t-stat wasn't opening right it could get that hot pretty fast. if it is closed the engine gets hot then it opens quick the temp could go up fast. Remeber it's not the actuall temp of the block but the temp of the coolant flowing over the sensor right after it passes the t-stat, well at least on most gas engines, not sure on tdis. It still could be a ground,.

[TDI Guy]

I thought the TDI's are cool runners? I have to find out what normal running temp is and what is considered hot..

[Mike Hippert]

They are cool on the trail, but when under load like on the highway they will warm up. Most TDI owners I know of always run a bit on the warmer side on the highway.

[TDI Guy]

IT was actually even showing it was warm out on the trail when rompin around. I wish i new where to start lookin.. Wiring?? or could it have been accurate?? Thermostat sticky?? Does the coolant have to be mixed 50/50 to cool properly?

[jimmy salmon]

i took my fan off of my 300tdi and ran it summer and winter that way with no over heating

[TDI Guy]

Huh. thats cool. if it was accurate, maybe my thermostat is sticking

[Mike Hippert]

Randy do you have a IR tremometer? If not I bet Vinny has something to measure the temp at the upper radiator hose, I would compair that reading to the temp gauge to see if it is accuret. Of course while driving down the road it is hard to do, but if you turn on the heat and if the air comming out the vent is too hot to keep your hand in front of then there is a good chance you are running a bit warm.

[JimC]

Randy - I think you're running the same VDo set-up that I am right? (I think I gave you the part numbers or maybe that was Chris Cox...)

Either way, mine does exactly the same thing. First time I drove in the rain with wipers and headlights on, I though I was overheating. For some reason, the guage is very sensitive to electical variations in the system. This is something I've just learned to live with since I'm now very comfortable with the effects of various accessories.

I've pulled some trailers up mountain passes and have run the temps up past 220 when I know I was making serious heat (and the EGT's were north of 850) Everything hung together fine and temps came back undercontrol quickly when the load backed off.

On a side note - I've got almost 20k on the Tdi now and its power and smoothness seem to be still improving.

[TDI Guy]

Jim, you did give me that info. I still have to do the EGT guage one day. I feel much better after you said that. I was freakin out about it. IT was the first time I was in the rain with all the electrical stuff on. Any Ideas if its fixable? I also was loosing power on the way home and had the gas pinned at some points. when I got home I looked at the limit screw on the peddle and it loosened up. I was only getting 1/2 throttle out of the truck..lol I was kickin myself. It must have been like this for a while too. I readjusted it and wow.. Tons of pep now..lol its runnin like a raped ape..

[Roadsiderob]

FWIW, I went round and round with a temp gauge problem on a NAS110...I found that the factory battery cut off switch (on the ground side) had enough resistance across it to cause the gauge to read screwy even though the rest of the truch was fine. Also, ground placement on these trucks is wierd...the d110 that I just had LineX'd has the main body ground sandwiched between the seatbox and the frame and held down by one of the seatbox bolts...and it was rusty and nasty. Bad grounds will do lots of fun things...electricity will find a ground, even if it's through another circuit. I had a ground problem on another 110 that would cause the windshield wipers to go every time you keyed the CB mike. Don't be afraid to add a few new grounds if you think it will help.
Rob

[TDI Guy]

Rob, so u think I should run a separate ground and that might help?

[Buckon37s]

Easy fix. First off, 195 is the recommended operating temp. If the engine, and the gauge, and the cooling system is working properly, no matter how hard you push that engine it will never go over 205. I don't care what you do to it. As to the fix, first make sure that the wiring strait off the sender is very well connected and insulated. Then go to your battery box and hook up a nice large guage wire straight from teh negative on the battery to the body. I hooked mine up all in the battery box. Shoule take you all of 5 minutes. Then open up your dash and run your guage grounds all to a mounting point on the body. Anywhere back there is good as long as it is a solid ground. And your done! Now, you owe me $20 for this information. I take cash or Paypal. Thanks

[Mike Hippert]

Rob, so u think I should run a separate ground and that might help?
Randy as a tes get the gauge working funky with the headlights, then run a ground right from the gauge to the battery to see if the problem goes away.

[TDI Guy]

Thats a good Idea.. Oh and David, what about that fuel guage? Remember I will bail U out of jail next time.. :)

[Buckon37s]

The gauge is free, but now you owe me $20 for my perfect advise. PM me your address and send me a hole cover thingy

[TDI Guy]

YOu got it.. lol

Follow-up Post:

Just ordered the blanking plug for you David... And sent you an email.

[TDI Guy]

Ok. Finally fixed this also. My original ground only went from my battery to the trans. So I went to the local boat store and got a big ass ground cable (#4) and bolted it from the ground on the trans right to the frame. Problem solved. The gauge now reads perfect and when I turn the lights or any other equipment on, the temp gauge does not climb up to 250. It has stayed steady at about 180 now... :) :) :proud

[JimC]

Wonderful, I looks like I shall be doing similarly soon.

[Campbell]

I'm having this same problem with my temp Gage going up with a lot of power on. Can you tell me where the ground is ib the trans and how you wired it to the frame. I get the ground from the neg side of battary to the box.

Thanks

[Campbell]

This morning I fried my second light switch in a month!!! Thing was cooked!

The light switch was also causing my temp gauge to move higher when I put the lights on.

This is crazy!! Gotta love these land rovers.


Any help would be great.
Thanks