[jonno_racing]

ok i am having issues with my zook...

new thermostat in near new water pump, near new jimny radiator, coolant even..

90% of the time its spot on.. in traffic, highway etc..

occasionally it gets a little warm.. ot is 82' and it might get to 90' the issue is it wont come back down.. it gets hotter, not seriously hot, but instead of cooling down it will go up to like 100' then really quickly jump back down... and it will do this again and again and again, till i shut her off for 20 or so min and let it cool back to 80 ish then it will be fine...

i am thinking the brand new thermostat is sticking shut? it is very annoying since the thermostat is less than 1000km old...

[jonno_racing]

also i stoped at 110' and the engine appears to be hotish... but the radiator cap was cold...... so no flow?

[v.w.dave]

Mate I chased a slight over heating problem for ever to find it was my t-stat stuck half open. hot sure why but that was the problem.

[ball]

airlock somewhere maybe

[Zook_Fan]

take the thermostat out for a while and see if that works. that way you will know for sure if it is the problem and it shouldn't matter too much if the engine takes a bit longer to get to running temp.

[89_tintop]

What brand was the thermostat??


I have had issues with tridon brand thermostats in various cars causing similar problems.. Everytime we chec em the test ok. Change to a different brand and never have a problem again.

[jonno_racing]

it is one from repco... daycon or something??

i am thinking of drilling a 6mm hole in it!... better to be safe than sorry..

i would have thought over 1000km it would have pushed any air lock out???? might point the front end high up and bleed the cooling system out tho.

[Scrawny]

What gauge are you using? Just the standard one or some digital one? What fan? Does it have a shroud?

[jonno_racing]

speco silver face electric...

thermo (although it doesn't seem to matter if its on or not.)

i dont think this is a guage issue... pop the bonnet when it is saying its hot and the motor feels hot.. (if that makes sence) and it only does it in time with the driving style..

i am thinking i might lash out and get a new thermostat from suzuki.

[Scrawny]

Leave the thermostat and bleed it properly first. Make sure the heater is on hot and leave the cap off till it is up to temp. Make sure the fan is kicking in when it should. I've never had a problem with new thermostats, not saying it could be the problem, just check everything else first.

[v.w.dave]

oh an check you timing if its to far advanced it will make it run warm...

[zookfun]

mk2/3 gti motor:

TFS225 fan switch: Temp Range: 95ºC to 90ºC
TT239-180 Thermostat: Opening Temp 82°C

Might be a blocked thermostat or radiator... 100degrees is fine since the electric fan is only meant to come on at 95! 110 is a bit high though..

Could be an inaccurate aftermarket gauge giving a false reading??
If the radiator is cold though, sounds like another problem@\

[Brett]

sounds like a air bubble or the thermo stat is in the wrong way so it doesn't want to open.

[jonno_racing]

will try to bleed the system again today... any how did you do yours nathan?

radiator is good.... and thermostat is new.. i will try to see if i can get any air bubbles out today...

if not i will see if i can get a new thermostat from Suzuki...

i am 90% sure its round the right way...

[Zachius]

You run a GTI motor right?

I would suspect that the custom piping from the water outlet at the back of the block to the radiator (not sure where your thermostat housing is?) has an airlock in it.

[jonno_racing]

yeah i was thinking that.. although the pipeing sits quite nice as straight now...

any idea on how to fix this?

[jonno_racing]

also how would a air bubble be causing it to act like this?????

[Hybrid]

I agree with it sounding like and an air lock somewhere. Depending where the bubble sits it can cause the coolant flow to stop, then once it moves the coolant starts cycling again which would drop your temps back down. Did your thermostat have a small hole in it? I think think the repco ones do. This is to aid in bleeding the system. It needs to sit to the top (at 12 O'Clock). Before messing with the thermostat or drilling it out why not do what was mentioned earlier and run it without just to test if its the thermostat or something else.

[jonno_racing]

yep cool i will pull the thermostat out today...

don't think it did have a hole..

also i would have thought after nearly 1000km of driving it would have pushed the air lock out?

[jonno_racing]

ok well i got the day off work.... so just pulled her out....

on the stove it appears to open and shut perfectly...

i am guessing its not the thermostat........

question is.. where is the air lock and how do i get it out?

i am thinking about a small hole or 2 in it to help the bleeding process tho...

thoughts??

also i dont want to run without a thermistat atm as it is a brand new bottom end and i a a bit paranoid about temp!

here she is tho... it has no quick bleading holes...

[jonno_racing]

ok well i have cracked the sads and ordered a new thermostat from Suzuki $38

should be here in a few days.

i figure better safe than sorry..

thing is how do i go about bleeding the system.. thinking about parking on a very steep bank? nose up?

[Zook_Fan]

start it with no radiator cap, slowly rev it until the water stops bubbling. then rev it hard enough to drop the level of the coolant and wack the cap on.

[LAY80N]

You probably have posted some in your members thread, but post up some pics of your engine bay, especially your custom radiator fittings/hoses. It sounds very much like you have an air lock somewhere in the system.

Layto....

[jonno_racing]

kk pics...

radiator imputs/outputs are in the same spot as standard.. so thats no issue..

i am thinking it may be in the top radiator hose... it dips down and back up in2 radiator...




the hose now go's straight from the 90' in to the thermistat.. got rid of that crap bend!

[Brett]

what about the hoses to the heater? make sure you bleed it with the heater on as well

[flaxton123]

i would get a coke bottle and cut it in half and stick it in the radiator cap hole and if it is abit to small use some tape to take up the gap and fill it with water and bleed it that way i do it at work with gay hondas because they get air locks and my mate gti motor had the same problem he made a bleed pipe that was higher than the engine worked

[atari4x4]

flaxton123 wrote:

i would get a coke bottle and cut it in half and stick it in the radiator cap hole and if it is abit to small use some tape to take up the gap and fill it with water and bleed it that way i do it at work with gay hondas because they get air locks and my mate gti motor had the same problem he made a bleed pipe that was higher than the engine worked

x2,

i have a similar contraption, powerade bottle with a short length of hose to get some extra height & some wire bracketometry to hold it up when it gets hot.

[zookfun]

when I put coolant in mine all I did was fill it up and then I ran it for 5 mins or so and topped it up a bit when the thermostat opened.

I dunno if it would be an air lock after you have driven 1000kms...
No kinked coolant hoses??

Any blockages? I seriously doubt its this but it did happen to a mate of mine- we thought it was a bad waterpump and then it blew all this junk through to the radiator..

Is the waterpump working ok? You can check by looking through where the radiator cap goes, and when the thermostat opens you should see a reasonable flow...

Another thing you could try is a radiator cap that has a temp gauge on it- these are really handy, Ive used it before when a faulty temp gauge has been throwing me off...

Good luck, hopefully some of these ideas help!!

By the way, is the radiator fan on when you are getting these temps?

[zookfun]

Yeah it could be like you said, a radiator hose going up and then down to the radiator... Stuff like that could cause an air lock but normally you wouldnt get one.


Darn, 38 bucks! Suzuki huh.. how do they sleep at night lol

[Ridge]

definitely an air lock, i had the same problem a couple weeks ago.