Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

Idle knock. Thermo fan relay issue

Vtrobbie

New Member
Joined
Sep 5, 2020
Messages
1
Reaction score
0
Points
1
Age
29
Location
New South Wales
Members Ride
2000 VT commodore V6 3.8L petrol
Need some expert advice got a 2000 vt V6 series 2 with an engine knock have done some work leads, plugs, coils, compression test, spark test, stuck a multimeter on it, throttle body cleaned, changed oil pressure sensor, radiator plus hoses, new oil (Penrite 10w40) oil air and fuel filter.

Haven't done maf or tps and at the moment pulling the motor is not an option right now but will be put through a full tear down and diagnosis and rebuild getting a scan tool on it this week. Will clear codes and rescan to be sure of fault codes

I think it's bottom end somewhere. It idles rough cold or hot almost to a stall drops to about 150-200 rpm then comes back up to normal rpm. When it gets up to 60km/h it starts jerking and pulling rpm drops aswell if you drop down to 40-50km/h it is less noticeable

Also have a cooling issue done continuity test on the relay for Thermo fan that needs replacing but a test with one from a running car still nothing from either fan test light indicates there's power from the fuse box to the relay already tried unclipping the radiator temp sensor fan don't come on. Did a coolant flush and put it a brand new radiator (auto) in and did the Thermostat after unbolting the thermostat housing there was no thermostat so the is some kind of electrical issue causing the thermofans not to come on regardless if the AC is on or off I don't want to put a new motor in with a major electrical causing the thermofans not to work

All of these issues and no check engine light or anything displaying on the dash as of right now no longer driving it till issues are resolved with the knock, electrical & cooling would really appreciate some advice on where to go from here. Very very sentimental car to the misso and trying to keep it as stock as possible please help
 

gtrboyy

Well-Known Member
Joined
Jan 25, 2006
Messages
4,253
Reaction score
2,737
Points
113
Members Ride
vt ss & lc gtr
If it had no thermostat probably ran too cold that thermofan won't come on untill hot enough.

Most relays are same just swap around under fusebox to one you know works for quick fix.

Knock may be balancer doing a wobbly...check youtube what to look for,most common things on these will have youtube clips lol

If no fault codes come up means external issue is possible like plugs/leads/coil packs/fuel pumps etc IF there is an issue when no fault codes.
 
Top