Author Topic: 83 1.6d overheating (Read 4452 times)

rare-hare · « **on:** March 27, 2009, 07:36:00 pm »

i have an 83 rabbit with mechanical gauges, the temp is very eradic, it will rise to 230 then fall down to the opperating temp of 190, the time it takes to drop is never the same, some times a few seconds, other times i have to pull over and kick the heater on full bore to get it to cool down. the thermostat is fine, it is the second one, i changed it just to be safe. i tested the old one in a hot plate of water and it opened fine, and at the right temps, when it started doing the same thing with the new stat, i pulled it and it works fine on the bench. but the engine still gets hot, the radiator was new last winter, the coolant system is not getting over-pressurized, and i am not mixing oil and coolant, so i think the head gasket is ok. the water pump seems to be fine, there is a constant flow of coolant out of the radiator overflow tube to the reservoir. also, i know the gauge is reading right i checked it with an ifared thermometer. when the engine is at 200, according to the thermometer the thermostat is closed, the lower hose is about 70 where above the t-state is 195 or more. how could a stat work in a pan of water but not in the engine, am i over looking somthing? any help would be great, oh by the way the pump and injectors are fresh rebuilt with all the fuel put to it that i can get and still get it to idle, I LIKE SMOKE!!!! but i have had other cars that were turned up and never got hot.

jtanguay · « **Reply #1 on:** March 27, 2009, 10:22:04 pm »

feel the rad to make sure its hot. your lower rad hose may be collapsing at high speeds. you also need to confirm that your rad fan is coming on...

rare-hare · « **Reply #2 on:** March 28, 2009, 05:56:17 am »

yes, it appears that the system is working fine, but it is still over heating. the top rad hose will get hot, and you can follow the cooling all across the radiator. the fan is comming on because i have it on a switch and i does not matter when i turn it on, the only way to cool the engine when it goes into its super heat mode is stop roll the windows down and turn on the heater. i have even pulled the block heater out of the block, the cylinders are not covered in rust or scale and there is no corrosion in the cooling system. I AM LOST.

Doug · « **Reply #3 on:** March 28, 2009, 06:41:36 am »

Chances are that your head gasket has begun to fail causing pressurisation of your cooling system with combustion gases leading to erratic temperature swings because of the pockets of (air) no coolant collecting in the head. My old rabbit did the same until I pulled the head changing out the head gasket. Then all was well.

Rabbit TD · « **Reply #4 on:** March 28, 2009, 10:40:55 pm »

Quote from: "Doug"

Chances are that your head gasket has begun to fail causing pressurisation of your cooling system with combustion gases leading to erratic temperature swings because of the pockets of (air) no coolant collecting in the head. My old rabbit did the same until I pulled the head changing out the head gasket. Then all was well.

I thought the same thing about the headgasket but he says the system is not getting over pressurized and has a constant flow into the reservoir. I've had trouble with most all thermostats unless they are the German type. I just went tthrough it on my new engine ARP studs and all, definately stay away from Autozone on the thermostats. I took the one out of the old engine and used it agin in this new one and it straithtened it right up and doesn't puke out the tank anymore either, by the way it's a 180 and not a 195 but so was the Autozne one I tried.

Rabbit TD · « **Reply #5 on:** March 28, 2009, 11:19:51 pm »

Are you really positive though that you are not getting bubbles in the coolant tank indicating headasket. Just for the hell of it try retorquing the head 1 bolt at a time and trying to save the valve cover gasket as much as possible to drive it to see if it helps, sometimes it actualy fixes it, it has for me before on the fiber ones in the past unless it's blown really bad. But it should make a little difference for the better at least showing you the problem if it doesn't cure it the whole way. If they are stretch bolts just reuse them for this check pulling them to 80 on the final of 3 steps and try it. If it fixes it just drive it but if you want to change to new bolts forget it and get the ARP studs instead because they really do work a lot better. We've done this on a few other cars other than these little diesels with success on them too, Toyotas especialy. Again if it is the gasket and it doesn't cure it the whole way it will make enough of a difference verifying that it is the headgasket anyway and sadly it almost always is but the ARP's help to keep it from happening.

rare-hare · « **Reply #6 on:** March 29, 2009, 12:07:48 pm »

i think i will try to run the engine without a t-stat, will that effect anything, i have never seen another engine with this complicated of a coolant flow. if there is no stat, will the coolant just follow the water pump bypass hose and go out the top rad hose without cooling the engine? the other thing i thought of is the engine will not overheat unless i am going down the road, it will idle all day and even cool down below the stat temp if it is cold enough outside, this being said if the head gasket is slightly blown and not loosing compression at idle, i would not see the air in the over flow line, i would need a way to get the car under a true load and then check for air. i think i am just going to pull the head, after 200k it probably wouldn't hurt to have a valve job. as far as the head studs go, i have heard of guys drilling and re-tapping the blocks to 1/2" and drilling the head to clear the larger bolts and use a grade 10 allen bolt in place of the old metric stretch bolts. a friend of mine did this to a rabbit he put a turbo on and used a factory head gasket and never blew it to the best of my knowlege. that would be much cheaper than an ARP kit i'm sure.