VZ SV6 Leaking coolant

[1FATVZ]

Hey guys,

Last week i was driving along and my temp gauge was going up higher than normal, it didnt hit the red and i didnt get any warnings but i pulled over and called my mechanic, i let it cool down and noticed that my coolant level was terribly low.

I had the car towed to him last Friday and he got back to me early Saturday telling me it was ready to pickup, im not 100% sure on what he fixed because i didnt pick the car up and talk to him but it had to do with some hose or something that he replaced along with a pressure test and a coolant top-up and i was ready to go, ($160 later)

When i got the car home later that night, about two hours later i noticed some coolant on the concrete under the car, i thought this was just some over fill so i wasn't too concerned. A few days passed nothing was leaking so i thought it was all good, a few days later i was parked at a shopping center and as i was leaving i noticed a decent leak underneath me.

At this stage the coolant levels seemed ok and the temp gauge was fine, i have been keeping an eye on it everyday and noticed that last night there was a leak once again overnight, but then nothing today,

The temp gauge is still looking good even after ~45 minute drives but if i keep loosing coolant im going to be back to ground one. I'm planning on giving him a call tomorrow arvo and probably going to take the car in first thing Saturday morning,

im just wondering if you guys had any ideas of what could be wrong and if you guys had any experiences with this happening.

I've got a photo of where i have seen the coolant slightly run from, from when i got it re-filled:

http://i875.photobucket.com/albums/a...IMG_0645-1.jpg

Thanks for any help in advance

[Torquative]

alloytecs are prone to spitting the water pump, thermostat and/or the coolant cap. I would take a guess its the water pump going off your photo as the coolant leaks from the pump, runs down the pulleys, pools ontop of the sump (where your arrow points) then runs off that and onto the floor., but thats just a general assumption

just type coolant or water pump into the search and see what comes up, pages and pages of it...

[mattsv6]

Agreed.

See here: Orange Fluid Dripping on to Sump?

[Dz811]

happened to mine, the holden water pumps are rubbish. Unfortunately there's no quick-fix for them, the seals on them are a joke

[slammedvz]

I would try a radiator cap first as it is cheaper, the caps allow the coolant into the overflow bottle but dont return them normally.

[2005vzute]

exactly right slammed vz...i changed mine yesterday..20 BUX IT COST ME..but yea, youll find with a hell of a lot of these holden caps that the top seal inside them turn to rubbish pretty quick...the coolant will bypass the seal attached to the spring like it should...you'll see at the bottom of the cap in the centre there will either be a plastic or metal little disc sorta thing...you can pull it out about 5-7mm or so...when the system cools down it creates a vacuum and the coolant from the overflow bottle comes through that little plastic or metal disc that can pull down...what happens instead, is that the top foamy rubbery seal will become shit, and instead of sucking coolant from the overflow, it sucks air in from the outside because the top seal isn't sealing like it should.

im not saying that's what it is...but part of diagnostic work is to start with the simple cheap parts...example...theres an electrical fault somewhere...why start looking at control modules and broken wires when it could be a 50c fuse

cheers mate

[1FATVZ]

so its either got something to do with the waterpump or the radiator cap, how can i tell if its got something to do with the cap, anything to look for?
cheers.

[JHULLZ]

Also make sure you have the screw type hose clamps on all four ends of the radiator hoses, the original clip ones are no good and leak after the hoses have been changed!

[Torquative]

true /\ and I believe there was a recall in the day to change them over to screw type. Actually I had a power steer hose come free for that reason (original hose clamp gave out)

If its the water pump you'll see it piss out with the engine running, that's my experience with them anyway. It is a known fault

[2005vzute]

in your radiator cap, when the ugly side is facing you (the side with springs ad rubber etc) have a look in the very bottom and theres a foamy/rubberish kinda material there, if that looks ****ed, replace the cap...if the rubber seal at the end of the spring is damaged, replace the cap...also just "trip" that little disc in the centre should be either gold metal or black plastic...just pull it out and let it go...if it was hard or sticking or anything..replace the cap..also if you do replace the cap, only go genuine..theres abit to look for if you buy aftermarket stuff...kpa rating, depth etc

just check with where the coolant pisses out from with a cold engine...all leaks and faults will happen with a cold engine..all the rubber seals and hoses etc are hard and are not sealing properly because they're cold..it could possibly stop when it heats up

[1FATVZ]

radiator cap looks fine, i think the cap should be ok as the cooling was pressure tested last week when taken into the machanics,

its going in on monday morning, ill tell him to have a good look at the waterpump, anything else i should tell him?

thanks guys.

[1FATVZ]

after having a close look under the hood earlier today, i have spotted coolant running marks (where it has dripped down) from the top frount of the engine, the cars going in early tomorrow,

what do you guys reckon it is?

[Torquative]

as mentioned earlier the water pump, but prove me wrong!

If its leaking from anywhere around #1 (or behind #5) on the attached image, then its running down the engine and pooling onto the sump which sits behind the harmonic balancer #2 on that attached image, like in your photo, then its the water pump, as #1 is the water pump housing and #5 is the water pump pulley.

[1FATVZ]

looks like the waterpump could be the cause, but could it be leaking coolant upwards? as i can see runmarks down from the front of the engine :/

[Torquative]

when mine let go it sprayed everything from the bonnet liner to the ABS pump

[1FATVZ]

Now this is really fu**ing with me now, got the car back last night after my merchanic replaced the water pump, im about to leave this morning and i let the car idle for about 5-10 minutes when i see it leaking again! It is once again coming from the frount of the engine and leaking onto the sump where it drips down to the ground...

I immediatly called my machanic and took the car down to his workshop,
We pressure tested it and coundnt find a leak anywhere, there was three of us inspecting all around the engine but nothing could be found, we started the engine and let it run for around 15-20 minutes with once again no leaks.

As it has leaked first thing in the mornings after sitting overnight, the car has been left with the machanic and hes gunna once again pressure test it once its completely cold later this evening.

Hes gunna give me a call once hes pressure tested it and he reckons it could be something under the top manifold And is running all the way down.

What do you guys reckon?

[1FATVZ]

Also just though i would add that the radiator cap was also changed yesterday

[slammedvz]

Thermostat housing oring

[1FATVZ]

Wheres the thermostat housing o-ring located?

[2005vzute]

sounds like it could be hoses or seals somewhere...i dunno if i mentioned on here before, but even your mechanic should know this..that you will most likely find your leaks with a cold engine..the rubber seals and hoses are hard and stiff and won't seal or fit to housings and the like aswell as it does when they're hot and soft.

[1FATVZ]

well the mechanic calls me today and tells me he needs to take the manifold off to find the leak as he has found it leaking from the back of the engine, this cannot be good...

if it is leaking from the thermostat, where is it?

[V8Silverfox]

Also make sure you have the screw type hose clamps on all four ends of the radiator hoses, the original clip ones are no good and leak after the hoses have been changed!

This is exactly what happened to my brother-in-laws VZ SV6, turns out it was the bottom hose clamp, this was replaced with the "screw-type" hose clamps ... problem solved.

[Torquative]

I haven't seen the thermostat as I haven't had to change one (yet) but I'm told its at the rear of the engine, somewhere near the transmission.

I'll say you prooved me wrong though, kinda hoping you wouldn't because this doesn't sound good from what your describing. Keep us in the loop tho.

[2005vzute]

yeppp, thermostat's at the back of the engine...if i had known this yesterday i woulda taken a picture of the back of the alloytec engines at TAFE yesterday and shown you where the thermostat was..ahh well, if anyone still wants to see what it actually looks like just tell me and i'll take a pic of it next tuesday

[FnomnaVZ]

pic here
Location of thermostat housing on alloytec SV6 engine