86 Golf update cooling system question, replaced tstat

[Heinz CA.]

Put a new stock tstat in as old one was ERRODED and was running to cool, thus only 25 mpg i beleive, now she runs hot? Cooling fan didn't come on, know it works, has come on before, should at 190 I think? i KNOW I put tstat in right, only one way and with a rubber o-ring(like Toyotas), or ne tstat bad?(happens rarely)I'm thinkin I need to burp system to get all air out, also put in new res. tank to block hose and cleaned out resevoir and reinstalled. Lemme know if any other hints. thanks!

 

[Skinnywater]

Re: 86 Golf update cooling system question, replaced tstat

Your VW requires a bleed proceedure. You can be confident the system is bled if the heater blows hot.<br />Just to make you very aware. New VW waterpumps and OE rebuilt waterpumps are likely to have plastic impellers and it is common to have them shear away. Depending on your '86's replacement history beware of that possibilty before you go replacing the radiator.

 

[bandit86]

Re: 86 Golf update cooling system question, replaced tstat

190 s not hot, it's right up there in normal, just because your gauges say hot, the fan not need to be on as it should have a separate sensor

 

[Heinz CA.]

Re: 86 Golf update cooling system question, replaced tstat

Well, heres latest, drilled 3 1/8 holes in tstat, heater does blow hot after tstat opens up, got to almost3/4 on gauge, fan didnt come on, think I need new fan sensor. That car has been running COLD for ages! Orig. tstat was eroded, weird as I hear fan come on a few weeks ago???? have tsta in correct, tested it in boiling water, it works. Gotta be fan sensor??? Radiator deosnt seem to be clogged, flushe system a few times a week and is running clear finally - and after replacing nasty rust covered hoses(inside), all else looks good, but prob. need to change timing belt(is at 95K now), please keep hints coming! <br />P.S. What a basic engine to work on!

 

[tommays]

Re: 86 Golf update cooling system question, replaced tstat

if other parts of the cooling system are showing corrision i would think at the least the raditor needs to be cleaned buy a shop<br /><br />tommays

 

[whywhyzed]

Re: 86 Golf update cooling system question, replaced tstat

try swapping the fan relay with a relay from another circuit (make sure they're the same part number- should be several the same)<br />Has it been raining there?<br />Check the windshield seal isn't leaking onto your relays and fuse panel... don't recall if that was still an issue in 86....but on some earlier Golf/Jetta was a chronic problem

 

[Heinz CA.]

Re: 86 Golf update cooling system question, replaced tstat

New OEM regular temp Tstat works fine, I tested it, is in correctly(impossible to fit it any other way) 1.8 4 banger,new hoses, radiator seems fine, system continously flushed last few weeks, runs crystal clear, replaced elect. cooling fan sensor that goes in lower driver side radiator. Fan WORKS if I hot wire it. Red wire TO sensor is hot, seems other two that go from there to fan are NOT getting hot. Also fuses all good, replaced with good known. What next? Don't see any cooling system blockage and ran perfect but way too cold before as that tstat was wayyyy erroded. I think water pump fine. It goes to a bit over 3/4 and then I shut it off, just to be careful. Is ther another solenoid I'm missin here??? Don't want to run w/o tstat. Can't find a relay for it per se, I beleive fan just comes on from sensor????Any advice would be great! Thanks!

 

[whywhyzed]

Re: 86 Golf update cooling system question, replaced tstat

you need to find the relay<br /><br />it should be one of the square things on this thing:<br />

 

[dolluper]

Re: 86 Golf update cooling system question, replaced tstat

If your running high on heat and the fan isn't coming on it's either the fan relay,wiring,or coolant temp sensor.......

 

[ezbtr]

Re: 86 Golf update cooling system question, replaced tstat

well I think it's fixed! Installed new rad. resevoir cap and fan comes on at 1/2 on temp gauge, cools, shuts off. Talked to guy at germanautoparts.com(excellent service, parts, prices and advice) and old cap probably wasn't bleeding enough? and letting sensor know when to open? Am thinkin bout also replacing water pump, - (they say return tube to resevoir should be spitting water constantly to resevoir?) as probably orig. and system was so corroded, radiator seems fine. Lookin fwd to better MPG now! Was gettin 23-25. Keep any hints comin, Thx!

 

[whywhyzed]

Re: 86 Golf update cooling system question, replaced tstat

those German engineers.....<br />thanks for the update... good to know... next time someone has a VW question, I'm just gonna say - "the clutch bearing's on the east side of the transmission and the cooling system's bizarre"<br />