Author Topic: My 1982 TD (Read 40391 times)

BlackTieTD · « **Reply #45 on:** April 02, 2007, 02:57:34 pm »

I replaced the thermostat today with another brand new unit from the dealer. Tested it first and it opens properly. But the car still overheats!!

The lower rad hose remains COLD even though the engine is on the last tick before red. The waterpipe that has its port directly above the thermostat in the waterpump, is HOT. Very hot. So if the thermostat works, the water in the pipe directly above the thermostat is HOT, why isn't the thermostat opening?

The rad remains relatively cool, with the rad cap off the coolant in the rad is about the temperature of soup to the touch...

I worked out a bunch of air bubbles and filled the car facing up hill. Filled through upper rad hose first, then the rad.

I don't think the coolant is circulating through the rad but it makes no sense to me at this point why not......

jtanguay · « **Reply #46 on:** April 02, 2007, 03:17:54 pm »

looks almost like we should join forces on this to figure out wtf is going on!

today i drove the car... and i gave it a good run and got the temp right up there! stopped in driveway, left engine running. at first rad was lukewarm... i could put my finger on it and not get burnt. about 20-30 seconds later i touched it, and it was nice and hot... could burn my finger after 2-3 seconds of touching it. still, fan did nto come on.

temp gauge still in the area that my rad fan would normally come on.

so at idle the coolant circulates through the rad, but not at driving speed. i'm also thinking that when the coolant was circulating through the cold rad, it didnt reach the proper temperature to kick on the fan, so thats cool. the fan did kick on for me when i was doing the lubro moly diesel purge though, so i know it works, and i confirmed where the gauge sits (halfway over from center of the gauge).

this cooling system issue is such a PITA!

BlackTieTD · « **Reply #47 on:** April 02, 2007, 07:34:40 pm »

To determine that the thermostat is not opening, that the temperature gauge is correct (or close), and to ensure that I can get to work tomorrow, I put a cut up thermostat in the car. Doesn't overheat now, stayed cool, so I put a pizza box over 2/3 of the rad. Test drove to work, running well :lol:

Their was serious coolant moving through the rad visible with the cap off as soon as I started the car. I think I must have had a horrible airlock somewhere. I did notice the rad level drop off considerably after the car was running for a few moments.

Going to drill a hole in the new tested thermostat and try that...

burn_your_money · « **Reply #48 on:** April 02, 2007, 08:46:39 pm »

Good call on brutalizing a thermostat, I'm glad that worked for you. Don't run the car too long like that because the oil will not get hot enough to evaporate the water in it which will lead to serious problems. Not to mention that your mileage will suffer.

jtanguay · « **Reply #49 on:** April 02, 2007, 09:08:33 pm »

hmmm i hope thats my problem too... dealer t-stat! i didn't check mine... i thought their quality control tested them already at the time...

hopefully i just have an airlock somewhere in the system!

BlackTieTD · « **Reply #50 on:** April 03, 2007, 06:42:04 am »

It seems that as soon as there was no thermostat in there, the airlock was able to purge itself. The coolant was definitely not circulating through the rad before with the proper thermostat in. I figure this must be why people drill their thermostats, to purge air, so I'll try that. I'd rather not do this because it will take longer to get the car to operating temperature, but I hope that this will no longer be a winter-driven car so I'll see how it behaves in the warmer 6 months of the year. Will be the 5th time dropping the coolant in a few days :lol:

What I don't understand is why it started overheating in the first place. I hadn't messed with the cooling system in a year or two, it wouldn't get airlocked out of the blue. I guess the thermostat or waterpump was the original problem, but then the problem became an airlock after the initial problem was solved.... :?:

burn_your_money · « **Reply #51 on:** April 03, 2007, 07:36:18 am »

Quote from: "BlackTieTD"

What I don't understand is why it started overheating in the first place. I hadn't messed with the cooling system in a year or two, it wouldn't get airlocked out of the blue. I guess the thermostat or waterpump was the original problem, but then the problem became an airlock after the initial problem was solved.... :?:

That does sound logical. I always drill a small hole in my thermostats, you hardly notice the increase in warm up time. I think I used a 1/8th drill bit

jtanguay · « **Reply #52 on:** April 03, 2007, 11:57:38 am »

i wonder if it would be worth splicing in bleed screws... to bleed out the air that way?

jtanguay · « **Reply #53 on:** April 03, 2007, 03:51:19 pm »

well i went out today and ran the car up to temp with the cap off. i revved the crap out of it (probably 3000rpm or so... MY EARS!! :lol:) and funny... the thermostat did NOT open at 87C (last year it opened at 86.5.. thats when it started dropping) then it reached 88C, and then i started squeezing the rad hoses to try and get some flow... and then the temp started stabilizing... i ran it for another 2-3 mins and the temp did not rise.

i'm letting the system cool down with the cap still off, then i will take it for a drive!!! damn i hope this fixes this PITA problem!!! i do NOT think it's my water pump now. if it was just bubbles i should have just fixed that in the first place... damn!

BlackTieTD · « **Reply #54 on:** April 03, 2007, 04:05:03 pm »

do you notice the coolant moving out of the small overflow hose?

i put a reservoirless rad in the car which surely wasn't the wisest move, but at least i can physically see the coolant moving vs. still with the rad cap off which is mainly just good peace of mind.

i covered up most... here i'll go take a pic:

i covered up most of the rad... just a slit top left above the white part of the pizza box folded over. depending on how i fold that flap the car will cool differently. :lol: doesn't take much!!

i love the pizza box mod. it has to be the final touch of the hillbilly beater rabbit :lol: :lol: :lol: ...but i think i better clean it up a little :lol: [/url]

jtanguay · « **Reply #55 on:** April 03, 2007, 04:23:04 pm »

hmmmm pizza box mod!!! delicious pizza inside, and a clever way of recycling! :lol:

one thing i noticed was very good flow from the little hose going to the top of the reservoir. when i revved it up it was spitting out more coolant, so i think that my impellar isn't slipping...

i don't think i've lost much water, but i'll probably end up adding more distilled as i've lost 1/8 of a litre or less. not much but oh well.

BlackTieTD · « **Reply #56 on:** April 04, 2007, 09:57:48 am »

It sounds like the waterpump in your car is fine. For peace of mind it really isn't that big of a job... but why fix what aint broke?

jtanguay · « **Reply #57 on:** April 07, 2007, 10:13:18 pm »

well i got my cooling system up to temp again and at idle it could hold its temp day and night... fan kicks on accordingly. driving on the highway, the temps creep right up, and its creepin me out!!! argh!!! i will see about getting the system bled out professionally... this sucks!

it does seem to help though.. running without the cap. it takes longer to creep up now so i think i've almost got all the air out. patience i guess...

burn_your_money · « **Reply #58 on:** April 08, 2007, 05:49:24 am »

jtanguay hold old is your rad? Have you tried back flushing it? Even if nothing comes out you are still helping. Most of the crap in there is really fine silt that you can't see.

jtanguay · « **Reply #59 on:** April 08, 2007, 07:38:55 am »

Quote from: "burn_your_money"

jtanguay hold old is your rad? Have you tried back flushing it? Even if nothing comes out you are still helping. Most of the crap in there is really fine silt that you can't see.

the rad is probably original... i should have taken the hose and flushed it that way... i will try that when we get some nicer weather.