Wildly fluctuating temperature after service on SV6

[daveminchang]

Hi, i got sick of paying $400 a service from the holden dealership for an oil change so I took my car to an RAA approved service place to do the oil, fuel and air filters.

that was about 2 weeks ago.

temperature before service was solid on two bars on the guage, but i notice over the last week that the temp is fluctuating quite rapidly between 3 bars (never gets cooler than that) and half way up. yesterday driving back from Victor harbour it was doing it a bit more noticely but was keeping cool because of air flow at 110.

when i stopped at lights it was fine for 1 min and then as i got up to 60 it went right up to 1 bar below the red zone within about 15 seconds and then dropped back down to between points 3 and 4 on the temp guage.

it wouldn't have been something stupid the service people have done would it?

checked coolant when got home and it's all there, no leaks from hoses that i can see. is it likely to be thermostat or temperature guage sender is faulty? seems to go up to fast to be real temperature. it's not just the guage on the dash as the thermo fan runs the whole time to cool it down so the car things it's hot.

ideas?

[ashbox]

maybe your rad cap is faulty, cos i know they pressure test to make sure there is no leaks in your cooling system.

it could be possible that the thermostat is stuck slightly closed.

which holden dealer did you use before going to an raa shop.

$400 is quite steep for a normal service, esp when i've only ever paid $250 for all mine and i'm also in adelaide

[impulsive]

yeah, go pull your radiator cap off, i blew one once, car went REALLY hot REALLY quickly, then dropped down and then really hot. Pull it off and have a look at it, when i pulled mine off the spring had compeltely broken and seperatedc from the cap. they are sold at repco and supercheap for about $30, pick yhourself up a spare too..

[jaz_777]

hey mate, my bet would be on the thermostat starting to shit itself, seems ti be happening more and more now, there a pain in the ass to change but, my mate had the same problem on his sv6, after much work replacing the thermostat the problem was fixed, would reccomend doing it before it completely shits itself and your stuck on the side of the road with a cooked engine

[the_trademarc]

yeah, go pull your radiator cap off, i blew one once, car went REALLY hot REALLY quickly, then dropped down and then really hot. Pull it off and have a look at it, when i pulled mine off the spring had compeltely broken and seperatedc from the cap. they are sold at repco and supercheap for about $30, pick yhourself up a spare too..

Holden sell em for $20 via Spare Parts

Definitely looks like the signs of a busted radiator cap. Should replace before you do the water pump too.
Would need to top up the radiator after too, and even coolant if its quite diluted

[ashbox]

just also beware, your water pump may go not long after you replace the cap, a few people are starting to report this happening.

mine went a month after the cap was replaced.

[daveminchang]

thanks for the pointers people. i'll take a look at the radiator cap and see if i can figure out how to change the thermostat. i think i'll leave a dead water pump for a mechanic, hopefully it doesn't come to that.

thanks heaps for the feedback.

[ashbox]

the thermostat sits at the back of the motor just above the trans so that may also be a job for the mech.

[daveminchang]

ok thanks again. I took a look under the radiator cap this morn with a cool engine and it's got a black substance accumulated around the rubber so i hope that's not oil in the water. it's only done 90,000ks so surely i'm not going to have gasket or whatever problems already?

the spring seemed to spring alright. i'll just take it to the mechanics.

[the_trademarc]

ok thanks again. I took a look under the radiator cap this morn with a cool engine and it's got a black substance accumulated around the rubber so i hope that's not oil in the water. it's only done 90,000ks so surely i'm not going to have gasket or whatever problems already?

the spring seemed to spring alright. i'll just take it to the mechanics.

Mine had only done 45 when my radiator cap went, and then at 85. If you don't catch it soon, you could do a gasket and water pump pretty easily, because you're effectively running the car without anything to cool it down.

[dunzsv6]

Hey Mate, im having the same issues with my VZ SV6 and im also from adelaide, I have replaced the radiator and pump and again, the temp guage raced up to red, and sat there for a sec, and then "click" it comes back down to normal running temp once I pop the cap. At first thought it may have air locks, but now I have noticed a coolant residue running down the gearbox/Engine Join(check yours). First thought was head gasket, but Holden's believe it is the thermostat housing and gasket leaking. Getting fixed tomorrow. Will let you know if it fixes it. I would hope that after only 130,000kms it wouldn't have a blown gasket!!!!!!

[PRAVX II S]

Hi, i got sick of paying $400 a service from the holden dealership for an oil change so I took my car to an RAA approved service place to do the oil, fuel and air filters.

that was about 2 weeks ago.

temperature before service was solid on two bars on the guage, but i notice over the last week that the temp is fluctuating quite rapidly between 3 bars (never gets cooler than that) and half way up. yesterday driving back from Victor harbour it was doing it a bit more noticely but was keeping cool because of air flow at 110.

when i stopped at lights it was fine for 1 min and then as i got up to 60 it went right up to 1 bar below the red zone within about 15 seconds and then dropped back down to between points 3 and 4 on the temp guage.

it wouldn't have been something stupid the service people have done would it?

checked coolant when got home and it's all there, no leaks from hoses that i can see. is it likely to be thermostat or temperature guage sender is faulty? seems to go up to fast to be real temperature. it's not just the guage on the dash as the thermo fan runs the whole time to cool it down so the car things it's hot.

ideas?

Hey mate could be all the things above since i am a auto-elec i think electrical.
could be the coolant temp sensor.
Becasue you said seems to go up to fast to be real temperature.
get the daignostic on to it.

[bigdaddycool]

Maybe some of you guys have some dodgy tune on ur cars from a pre-owner..........

Bad settings will cause the car to knock and mass heat quicky...... Just seems too much of commonly odd problem. I'd probably recommend you take your car to eagers and have them do a factory update over the ecu as well just incase. I know for a fact theres big differences between 04/05 models and 06 models with their stock tunes.

Example: 04/05's run generally the same all the time....... and are slightly more powerful then an 06 if u got the air to back it up (eg highway) ......... where as the 06's are really designed more around temperatures, and thus are alot faster then a 04/05 model at night.

-=-

Ignore my jibbering........... I'm just saying, it could be a dodgy tune. When u throw it out u can easily heat a car any number of ways.

[f1tzy]

I have a flat tyre, im sure it tune related

[PaulSV6]

Maybe some of you guys have some dodgy tune on ur cars from a pre-owner..........

How come, nearly everytime someone posts up an issue! You think its tune related?

I have a flat tyre, im sure it tune related

[Danoz]

How come, nearly everytime someone posts up an issue! You think its tune related?

Bigdaddytool strikes again.

[the_trademarc]

How come, nearly everytime someone posts up an issue! You think its tune related?

I was deadset on posting the same thing! You beat me!

[the_trademarc]

Hey Mate, im having the same issues with my VZ SV6 and im also from adelaide, I have replaced the radiator and pump and again, the temp guage raced up to red, and sat there for a sec, and then "click" it comes back down to normal running temp once I pop the cap. At first thought it may have air locks, but now I have noticed a coolant residue running down the gearbox/Engine Join(check yours). First thought was head gasket, but Holden's believe it is the thermostat housing and gasket leaking. Getting fixed tomorrow. Will let you know if it fixes it. I would hope that after only 130,000kms it wouldn't have a blown gasket!!!!!!

It will depend on how long it took you to notice the issues and replace the cap and pump.
It could be it took you too long and the gasket has already blown? Any leaks from below? Loss of coolant pressure?

Let us know how you go, seems like you won't be the only one having these problems once the Alloytec's hit the 120k+ mark.

[impulsive]

ha ha, Bigdaddycrap solves another mystery.. you should join the scooby doo sqaud, a tune will sort out there van issues i hear they have been having

[diysv6]

Had my coolant changed by the dealer recently. All pressure tests etc OK, no leaks.
After reading this thread, decided to unscrew the radiator cap. Found two small cracks moving into the grooved ring made by the radiator cap sealing against the radiator housing. I had not lost any coolant and the overflow tank reads correctly. The rubber gasket had distorted and become oversize and was fouling the side of the radiator housing, such that when the cap is removed the brittle rubber gasket starts to tear and crack. This is original cap - build Sept 2004 SV6. The rubber gasket is very stiff and feels almost brittle in some parts. This probably explains where folk have had the service and then overheating etc happens after the service - for no real reason. About 3-4 mm of the rubber seal had folded out and around the screw in part of the radiator cap. So the gasket had become thinner and more prone to cracking when unscrewing. Cheap fix for less than $25.00
Thanks guys for the heads up.

[dunzsv6]

Well, worst fears have been confirmed, small blown head gasket on passenger side. It's only small as it only leaks around 300-400mls every 5-7 weeks. Holden says that they wouldn't even touch it until it is a leak as at the moment it's only a weep. Only problem now is that it is a $2-2500 job to get the heads taken off, machined, new gasket set is worth like 400 and labour is around 6 hours min!!!! very pissed off with Holden how can this happen to a 4 year old car? Where has the Holden quality gone? May aswell buy a Kia!!!!!

[the_trademarc]

Well, worst fears have been confirmed, small blown head gasket on passenger side. It's only small as it only leaks around 300-400mls every 5-7 weeks. Holden says that they wouldn't even touch it until it is a leak as at the moment it's only a weep. Only problem now is that it is a $2-2500 job to get the heads taken off, machined, new gasket set is worth like 400 and labour is around 6 hours min!!!! very pissed off with Holden how can this happen to a 4 year old car? Where has the Holden quality gone? May aswell buy a Kia!!!!!

Like I said, it depends on how quickly you took to notice a problem, if it was instantaneous then it would have been avoided. (I check my car everytime the temp hits halfway).
If you drove around for a couple of weeks with the temp gauge going all over the place, then there's a good chance you would damage the gaskets on any vehicle, Holden, BMW, Kia, Tata, lol.

So it comes down to how you treat a car, not how its built.
Ive seen 3-year old VZ SV6's that are in such bad nick I wouldnt even pay 4k for them. And then you have ones like mines which is nearly 4 years old, and the owners have taken care of them, that would still fetch min 18k on the market.

[dunzsv6]

I look after my car extremley well, and the temp guage sits at it's normal 2 bars 99 percent of the time and it seems only every 5-7weeks it would lift up to red and then drop back down to normal running temp once I pop the cap and release the pressure and add a tiny bit of fluid. That's why I replaced the radiator, pump and fluid not thinking that a modern car could pop a head gasket! My mech. Thinks that it was the reason the previous owner sold the car because of it. To make matters worse the car service history has been all done by one genuine Holden dealership and I don't understand why they hadn't picked it up before warranty ran out as I bought the car with 104,000 on the clock.

[the_trademarc]

I look after my car extremley well, and the temp guage sits at it's normal 2 bars 99 percent of the time and it seems only every 5-7weeks it would lift up to red and then drop back down to normal running temp once I pop the cap and release the pressure and add a tiny bit of fluid. That's why I replaced the radiator, pump and fluid not thinking that a modern car could pop a head gasket! My mech. Thinks that it was the reason the previous owner sold the car because of it. To make matters worse the car service history has been all done by one genuine Holden dealership and I don't understand why they hadn't picked it up before warranty ran out as I bought the car with 104,000 on the clock.

Hmmm in that case it could just be stiff luck! Lol!

[dunzsv6]

haha, oh well on the bright side, while the heads are off, I might have to get some porting and polishing done !!!! (and tell the missus that it is required) lol