VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: nissannx on January 16, 2015, 04:23:41 am
-
Car started over heating on highway only. Would always stay under half for the past 3 months. Now it goes past 250f. Half the rad is cold. The side that controls the fan is cold.
I tried searching online but people never reported on how they solved the problem. It cools back down at idle.
I'm going to take everything apart and flush it on Sunday. I will test my thermostat as well.
Any online write ups on how to remove the thermostat? I have power steering.
Anything else I should be looking for?
Thanks
-
The power steering pump has to be unbolted to get at the thermostat housing. You don't have to unhook the power steering lines, but the bracket that holds the power steering pump on needs to be removed (but the pump can stay attached to the bracket)
It's enough of a pain that I'd just buy a new thermostat and some fresh coolant. There is no drain anywhere on the cooling system, when you open it up you'll have a gusher of coolant that runs over all sorts of grimy engine parts making it not suitable for reuse.
Also make sure your thermostat comes with a new o-ring. Plus you ABSOLUTELY should replace the thermostat housing - it is made of plastic and rarely will seal well if removed and reinstalled. They are CHEAP, like under $10. It's a huge pain to have to get back in there again to deal with a leak. If your car has the two-piece coupler joining the lower rad hose to the thermostat housing it would be wise to replace that too. There's another o-ring that needs to be replaced as well if you have that bit. If the rad hose is connected directly to the thermostat housing then you don't have to worry about that part.
http://www.partsbase.org/vw/jetta-jem-us-1992-12100-coolant-pump/
-
Driving home wasn't good. Had to pull over 3 times.
Rad is ice cold but the rad hoses are hot. Does this sound like a failed thermostat? Would it stop coolant flow to the rad?
-
Yup.
Maybe a bad WP.
-
Does this car have the goofy split pulley on the WP?
-
The water pump has a groove for a belt to the crank and a groove for the alternator to the crank
-
I usually see the later WP pulley with the sheave that drives the PS pump... That split pulley will not drive the WP if the PS belt is off, since the alternator sheave is designed to run like an idler pulley.
-
the p/s pulley on water pump also goes 1 way; with a/c and w-o a/c.
-
The power steering belt is on and the power steering works. The belt is tight for the water pump
-
Another possibility is the impeller for the WP has come loose. When the t-stat is out, a screwdriver can be used to check if the impeller is still tight on the shaft - try turning the pulley while blocking the impeller with the screwdriver.
-
I prefer to extract as much coolant out of the system by siphoning from the reservoir tank before opening the lower hose. Low pressure compressed air into the bleeder hose makes more coolant rise into the tank.
Another trick is to shove a thin screwdriver into the lower hose along the t-stat housing (after removing the clamp), to guide coolant away from the dirty parts.
Both of the above methods are slower than just pulling the lower hose, but they help keep the floor tidy and reduce loss.
-
How does the flow into the coolant resevoir look?
It's common for the restrictor in the small hose to clog and air gets trapped in the block.
Easy fix for a common problem.
-
It wasn't moving then in 5 minutes just started coming out the reservoir.
-
if you mean the water wasnt flowing @reservoir tank; a blown water pump can do this; that means you have to drop the thermostat housing and see if impeller is just spinning. you need a new thermo, oring, coolant, and various other things help out.
if by coming out of tank thats it boiling in your block, ummm, i hope you dont plan to do that too much,,
-
I just ordered everything today. New housing oring and thermostat. Will check the pump once I'm inside.
-
you need vw coolant, correct one
-
Is the restrictor necessary? Can I just cut it out?
-
System will still work without the restrictor, it is really to bleed air. But when it plugs, air won't purge and the system can overheat.
When the restrictor is removed, slightly more coolant is diverted away from the radiator to the tank. No biggie.
You can use any coolant in a 1.6.
-
I just tackled this over heating problem. My restrictor was completely plugged. Had to drill it out. Also added straight water and rad flush and took it for a test drive. Engine was running at 195 and 200 if I stomped on it. Never over heated and the whole rad is warm again. Going to test the old thermostat tonight. Just waiting for the car to cool down to fill with proper coolant
-
You can use any coolant in a 1.6.
i dont happen to agree; that doesnt mean it will be a problem; vw coolant runs $28 or so.
-
Also added straight water and rad flush and took it for a test drive.
i run straight water thru 2X after flush, (fully warming up both times). after a flush you now are safe to use red vw coolant(if you already havent used).
-
I just tackled this over heating problem. My restrictor was completely plugged. Had to drill it out. Also added straight water and rad flush and took it for a test drive. Engine was running at 195 and 200 if I stomped on it. Never over heated and the whole rad is warm again.
So, a t-stat change and restrictor fix. Not too painful.
(WP change can be a project.)
Refill with coolant of choice, but don't mix the spendy stuff with cheap. Bad mojo.
-
Water pump still looks good. Has gold thick fins. Took it out for another test drive and so far so good.
Real test will be Monday.
-
Refill with coolant of choice, but don't mix the spendy stuff with cheap. Bad mojo.
dont use the cheap-o .
so after clearing you dont have much residue in the flush/mix?
replacing wp means timing work
-
The old thermostat tested fine so it looks like it was the restrictor. When I flushed the system a lot of scale came out
-
perhaps flush again; you can drive it like 50 miles max and of course drop (water) when warm
just dont drive so far away if something does happen
-
I have already added coolant. I will find more out Monday when I drive it to work
-
The old thermostat tested fine so it looks like it was the restrictor. When I flushed the system a lot of scale came out
Sounds like you have it solved. One thing that wasn't mentioned - you may want to either have the radiator rebuilt or replaced. Don't know how old your vehicle is but over time they fill up with crud and loose efficiency. The "lot of scale" is a clue to a plugged radiator.
-
I'm planning on swapping the 1.6td this summer. I'll make sure it gets a new rad at that time
-
It wasn't moving then in 5 minutes just started coming out the reservoir.
That didn't answer my question.
Could still be just a clogged line.
-
It wasn't moving then in 5 minutes just started coming out the reservoir.
That didn't answer my question.
Could still be just a clogged line.
It was a clogged line. It's posted above
Thanks for all your help everyone
-
Oh, sorry must have skipped the last page before posting.
Removing the restrictor will cause the coolant to enter the resevoir faster.
It can splash against the cap and the pulses of pressure in addition to the normal coolant system pressure can cause the pressure valve to open and leak a little.
I've seen someone build a splash shield to halt this when it became a problem.
-
I ended up leaving the restrictor just had to drill it out abit to remove the clog
-
It's probably one of the thinnest passageways in the cooling system so it'll probably clog again.
I've wondered if it should have a filter before it.
-
If your cooling system is clean and your coolant is in good condition there shouldn't be anything solid in the cooling system to clog it up. If your coolant is old and not working properly anymore or you've been using straight tap water for your mix then you may have dissolved solids that will clog things.
-
I've owned it for a year and have changed the coolant twice with fresh coolant and disttilled water. No telling what happened to this poor car before then
-
Have you ever run an actual flush? If it is clogging up repeatedly then there's still a lot of scale in there somewhere, would be a good idea to get it out. That stuff hurts cooling efficiency big time too.
-
I dumped a rad flush product in and drove 150km then flushed with distilled drove 50km them added new coolant. When I swap motors I will remove rad and give it a good flush