Cooling problem. maybe.

[VNCalais98K]

My car temp has been going funny lately.

Not overheating, but the temp guage is behaving different to normal.

When driving constantly, it drops to on or just below a quarter which isnt a problem.
When in traffic, it will climb (obviously) but lately its been doing it a lot faster, and when the thermo fans kick in it takes longer to go down.

The other strange thing is that when you give the car some revvs the temp will drop down again, whether thats taking off briskly, or just stabbing it a few times while stationary.

Checking under the hood i have noticed that after a bit of driving, the radiator bottle seems to be leaking coolant from the cap.

Im getting the feeling that there may be a blockage somewhere, or the water pump is not flowing properly.

The thermostat and housing are only 3 months old, and the water pump is about the same.

Any ideas?

[pete_squid]

generally when water pumps aren't working properly, you can hear it, they make a 'whirring' noise which you can check when stationary. Additionally, if your radiator is a little old/worn and a new pump is installed the additional pressure placed on the radiator will reduce it's effectiveness and you may be up for a new one too. Also be worth taking a look at the water in the radiator when the car is cool to see what color it is and whether there is any oil slicks in it.

[Burt_vn]

Yeah, along with pete, id be keeping a close eye on your oil, and your water, for traces of one in the other. I had a similar issue with an old laser of mine. Would heat up quite fast at stand still, but soon as it got air into it, it cooled down almost straight away. That was a blown head gasket, but id be hoping for you thats not the case. Id give your radiator a flush over the weekend and if your car doesn't have some sort of coolant mix in it, i'd drain the system and replace it with coolant. Also, just because the thermostat was replaced three months ago doesn't mean it cant fault. So don't rule that out either. I'm sure someone with more knowledge than me will hit this fault on the head by the end of the day though.

[VNCalais98K]

When I had my old telstar, that did a head gasket so I had that thought cross my mind here too.

Luckily, its not losing coolant outside the block, and its not gobbling it up internally (ie theres no residue in the exhaust) and lastly the coolant is dead green and the oil is dead brown, no sign of any mixing with either.

[pete_squid]

go with the radiator flush then, there is probably air in the system that is making it block. Let me know if you need tips on how to do this

[VNCalais98K]

Yeah well i drained it and refilled it and never ever bled it... that could be a problem.
How can i do this?

(if it takes more than a spanner and 5 minutes then maybe ill just take it somewhere haha)

[pete_squid]

The best way I have found is once you have refilled it, leave the radiator cap off, and run the engine. This will get the water moving through your system and the air will start to bubble out from the radiator...keep an eye on your temp guage when you do this and occasianally give the engine a rev. Once it has run for a few minutes with no bubbles of air switch the car off, top it up and hopefully problem solved.

[Burt_vn]

Yeah, Petes pretty on the money, give that a try as its the easiest and quickest. If the problem continues give your radiator a good flush. I would assume you dont have a pressure gun for it, but you can still get results from your garden hose, you should attempt to reverse flush it by sticking the hose in the bottom connection, and then pulsing the tap every 2-3 seconds, whether you do this with your tap control, or just by kinking the hose, it doesnt matter. This helps to dislodge bits of rust and **** thats collected in your radiator. Ive always used a pressurized flushing gun for it, but im sure youd still free up a fair bit from the flush. You'll be surprised at how much **** can build up in them. Good luck anyhow.

[VNCalais98K]

Well, in terms of bleeding it, I have been running it and topping it up for a little while, and i put some radiator stop leak crap in it (Wynns premium) to try and stop a small leak ive had since they replaced the inlet manifold (i cant see it but just smell it damn it!) and thats when its really started to warm up, so sounds like it needs some good flush.
I might take it somewhere to get it done properly with the pressure gun (especialy with the water restrictions, my neighbors would kill me if i did it with the garden hose in the driveway)

[Burt_vn]

Yeah, i was thinking water restrictions. The fact that you put the stop leak in and its started to head up is a big hint towards a blockage, that stuff stops leaks by blocking things, lol. Lets hope a good flush and shes back to normal.

[VNCalais98K]

Ok.
flush out is only going to set me back about $50 bucks, which is cheaper than a water fine, so thats no worry, EXCEPT.

The mechanic says that with stop leak the radiator can become blocked and just flushing wont help, they say may need to send radiator of to be "rodded" or something, where they clear it all out and then send back, in which case its more likely to be around $200.

Bloody hell.

Harmonic balancer last week, add to that the timing chain which didnt even need to be replaced. grrrr.

[Burt_vn]

Flush it first. Dont be sending your radiator off to be reco'd or anything, youd be better off buying either a new, or second hand reco'd radiator, get some quotes on them first. May end up being less than the $250 to get yours flushed and 'rodded'.

[VNCalais98K]

Yeah true, and if i just get the flush and still have the prblem i can pick up a recoed radiator, and switch it myself (thats an easy job i CAN do, haha) and then just fill and bleed. Viola!

Yeah, ok, sounds like a plan.

Thanks for the help guys, I'll let you know how I go.

I tell ya, I know the KM on this car are low, but its having all the problems I'd expect from a car with double the KM, so either the dash is swapped or Its had a hard life.

Well i guess it was pretty cheap so cant complain. still havent spent the insurance value yet, so i can come out in front if there was an "accident"

[Burt_vn]

haha. gotta love those 'accidents'
No worries, hope the flush fixes it for you. We could be on the totally wrong path. You never know with cars sometimes. By the way, just checked out your calais, very tidy mate! that engine bay looks immaculate. Just be prepared for your plastic idler pully to break any minute though. I've never come accross a VN that hasnt broken one or two of them. Should buy the chrome replacement, they are cheap, look better, and last a lot longer.

[VNCalais98K]

It doesnt look that clean anymore.
I had a busted manifold put coolant all over the engine, replaced it with a reco which is covered in****, and second already replaced the idler pulley with a metal one, and lastly added a cold air intake which fills up a bit more space.

Still a POS though, haha. Sick of the problems.

[Burt_vn]

Haha, oh fair enough. Yeah my VN has been giving me a few problems lately, but you get that with a car thats almost 20 years old! My only problem is the moment is an insanely loud lifter, which although i can do most things myself, ill need my dads (hes a mechanic) help to replace the lifters, and he can't help me out for a few weeks. So ive been driving my daily.

[pete_squid]

good to see it is all working out, and besides VN's notoriously need a bit of work between 120-150K. Including water pumps, radiators, alternators etc. But look at it this way once you have done the work she will be good for another 120-150K

[pete_squid]

Hey, btw either of you able to help me out with my problem...VN Broken into?? Basically I need a pic of wiring looms layout of a VN to compare with what has been done to mine. Thought I might give it a shot you could help if you had a digi cam

[VNCalais98K]

My wiring loom has been adjusted with the installation of my alarm.. anyone that tries to steal my car will have a hard time finding the alarm wires thats for sure :P

[VNCalais98K]

good to see it is all working out, and besides VN's notoriously need a bit of work between 120-150K. Including water pumps, radiators, alternators etc. But look at it this way once you have done the work she will be good for another 120-150K

I hope that you are right.
Im getting married in september and cant afford to keep throwing hundreds of dollars at the car.

[pete_squid]

good luck with the wedding, and unless you have a lemon (which I doubt because the problems you are having are pretty typical), you should be right...just a shame you aren't in Melb...could help you out with the work!

[VNCalais98K]

Ok, the funniest thing now.

Its the OPPOSITE PROBLEM!

yesterday arvo, got in the car, sat in traffic for 45 minutes on west terrace with the A/C on and the temp went to dead cold... DEAD COLD!

The needle was sitting in the lower half of the thick white bar that signifies the lowest temp...
When i drove a bit harder, it would rise up, but not significantly (around a quarter) and then as soon as i drove like a granny or stopped in traffic it would cool to dead cold again.

Im thinking mabye stuck thermostat... before was stuck closed now stuck open, or im thinking temp sensor as the thermo fan doesnt turn on on its own (even at 3/4temp), but it DOES turn on when i put the A/C on, but im not sure if the thermo gets its signal from a temp sensor or the thermostat.

[aussieghostrider]

yeah sounds like thermo fan fuse has died if it wont kick on at 3/4 temp.The aircon automatically turns it on so might be good idea to leave aircon on till you fix the problems to stop from overheating.

If you see coolant coming from the cap then it may not be fitted properly, there is a ring rubber seal that sits in it and can be pain in ass, Take off cap start car and let any air that maybe trapped out should take 2 mins or so to do this & make sure the coolants a nice green color and if need be top it up to about 1 inch below the cap.then get some grease and put on ring and place back in cap and put back on slowly this will get a good seal and stop it from coming out.

Ok The thermo fuse sounds stuffed to replace that is easy the fuse box is right near the coolant bottle $15 to replace, The fan should kick on by itself now when car hits 1/2 way on temo guage,Still problems overheating then next thing is coolant temp sensor.
you can do it yourself but the coolant temp sensor is at back of manifold and can be a prick to remove. Also its summer at moment the cars gonna run hot in lots of start stop driving & or sitting at lights for long periods. Best bet for you is get your coolant temp sensor,thermo fan fuse,radioator flush.

The radiator flush you can do yourself just undo both hoses and remove and if they look old replace them $15 each well thats what i get them for.Anyway get your garden hose with nozzle attactment and stick it full ball into all the inlet and outlets holes and watch for **** to come out, if you see rust/crap coming out keep doing this until water goes clear then put all hoses back on.

now make sure you got the 5litres of v6 series nulon coolant and 5 litres of distled water and mix 2.5 litres of each into clean bucket and pour that into bottle ( or if you have normal radiator cap then into that) start car and let idle to get air out giving car few revs now and then and I found squeezing the hoses back and fourth will get air out quicker, then replace the radiator cap,If you have a bottle it can be tricky to put back on i found using some multi purpose grease and rubbing that onto ring that sits in the cap will help keep seal just put the cap on slowly.Also your suppose to put these coolant tablets to stop leaks and lubricate cooling system from holden your suppose to throw in every coolant change but its up to you.

that should set you back $100 if not little more,just ring up places in phone book near you and get best quote.If after doing all these things and u still have problems maybe replacing the water pump then if still problems thermostat again

just to let you know ...
My Vn runs at just over halfway on temp guage if stop start driving in hot weather like it is now its summer the fan kicks in and goes back down,if i start driving then it drops way back down to around 1/4.My coolant is diluted alot also from a busted hose few months back as im too lazy to replace it. These cars run hot and need good coolant mix its 5litres of Nulon concentrate v6 coolant to 5 litres distled water.

Another thing you used stop leak stuff which yes can block radiator but if there is usually a blockage to biegin with.I have a small leak on timing cover which has been like that for 7 years and every now and then I put this stuff through called Car Go Stop leak it comes in a clear plastic bottle and has copper/silicon filings which fixes cracks good,they sell it at super cheap auto for $8 and it does the job.

[VNCalais98K]

Thanks for the advice aussie!

I have a few spare fuses so ill do a swap and see if that helps, the water pump is new also, so hopefully i can stop after temp sensor and fuse.
From what youre saying it seems my temp would be in the normal range (with the A/C on it wont go above half, 1/4 when driving)
Im thinking it must be the temp sensor, because the temperature fluctuates so wildly its impossible for it to be the actual engine temp.
It seriously goes from dead cold, then within 30 secs its up to half, then after a few minutes of not revving it with the A/C on it goes down to dead cold again.
Somethings all wrong there.

Anyway ill give the fuses a try and see what happens.

[anton1o]

Have you thought maybe about making a switch for the fan?
Allowing you to turn it on whenever you please