ve commodore cold start up noise/rattle

[1997 VT Calais Series 1]

If the noise you hear changes when you have the aircon on then I suspect what you are hearing might be external to the engine and not necessarily internal. External noise can sound like it is coming from inside the engine so I would check carefully on start up with the bonnet open and someone starting the engine for you testing both with the AC on and then off. For example a bad serpentine belt squeal on a cold start will sound terrible and will not necessarily be continuous(but often is) and can last only a few seconds or it may go longer until the belt warms. If there is a noisy bearing in one of the external pulleys that only makes a racket on cold start up (for now), that could be something to eliminate as the cause of an external noise although when these pulley bearings start to become noisy the noise is normally continuous.

From what you have posted it does not look like the Holden mechanics made any effort to detect and isolate the noise for you but just changed parts to get some workshop revenue from you. In particular I cannot fathom why, if the engine noise is internal, changing an "oil pressure switch" could actually do anything to fix a cold start engine noise(and it did not of course). The OP "switch" is only there to trigger a low oil pressure warning to the dash and probably a signal to the ECU. It does not do anything to affect oil lubrication to engine parts. Oil flow is run from the engine's internal oil pump, oil pressure is generated by resistance to flow and excess oil pressure is dealt with by the oil pressure relief valve.

By the way, check your owner's manual again on the optimum oil spec for your engine. You mentioned 5w-40 is what you are using. As in the later V6 engines, I understood the preferred oil was a 5w-30 for your 2009 engine. If that is the case I would not be using a 40 weight oil.

I agree with Sean880,

1) If the timing chain was the faulty part then you would have most certainly received a fault code.
If the timing chain was stretched and there is worn timing chain tensioners. At cold start you hear the timing chain slapping against the timing chain tensioners until oil pressure builds up but? Once you have this occurring it would definitely generate a fault code as the timing would not be in sync with the cams and the sensor would pick this up.

2) As for the AC, ( as mentioned by Sean880) I would be inspecting it at cold start up to see if the noise is coming from the AC Compressor (possibly a faulty compressor bearing, but I have never heard or known of one make noise at cold start only) Also check any other component that may cause the cold start issue like, belt tensioner, water pump bearing, alternator etc...etc... but at cold start I think your going to find that it is an Oil related issue.

3) Sean880 is correct, an Oil pressure switch will do nothing, it only monitors and sends data has no mechanical job of the internal engine.

4) Sean880 is correct again, the choice of Oil Brand and it viscosity is vitally important for these engines, 5W-30 is the recommended grade of oil but? In saying that my engine has done 380,000+ km's and is still performing well and I will at a later date move to 5W-40 after checking/testing the compression of the cylinders, but I am definitely using full synthetic engine oil and my choice of brand is Nulon Full Synthetic 5W-30 Long Life Performance Engine Oil.

 

[185OSS]

I agree with Sean880,

1) If the timing chain was the faulty part then you would have most certainly received a fault code.
If the timing chain was stretched and there is worn timing chain tensioners. At cold start you hear the timing chain slapping against the timing chain tensioners until oil pressure builds up but? Once you have this occurring it would definitely generate a fault code as the timing would not be in sync with the cams and the sensor would pick this up.

2) As for the AC, ( as mentioned by Sean880) I would be inspecting it at cold start up to see if the noise is coming from the AC Compressor (possibly a faulty compressor bearing, but I have never heard or known of one make noise at cold start only) Also check any other component that may cause the cold start issue like, belt tensioner, water pump bearing, alternator etc...etc... but at cold start I think your going to find that it is an Oil related issue.

3) Sean880 is correct, an Oil pressure switch will do nothing, it only monitors and sends data has no mechanical job of the internal engine.

4) Sean880 is correct again, the choice of Oil Brand and it viscosity is vitally important for these engines, 5W-30 is the recommended grade of oil but? In saying that my engine has done 380,000+ km's and is still performing well and I will at a later date move to 5W-40 after checking/testing the compression of the cylinders, but I am definitely using full synthetic engine oil and my choice of brand is Nulon Full Synthetic 5W-30 Long Life Performance Engine Oil.

My 2009 VE V6 SIDI Commodore has done 300,000 klms and is also making that horrible rattle noise every cold start up for the last few years. My mechanic son reckons it's the timing chain tensioner, which would be very expensive to replace. I keep a check on the oil level to make sure it's full. However it doesn't really make much difference.
Has any one had it solved?

 

[VTS5]

Last few years you better do something bout it,tensioners can push so much,, then;you'll end up with this, if not already..

 

[Skylarking]

... My mechanic son reckons it's the timing chain tensioner, which would be very expensive to replace. I keep a check on the oil level to make sure it's full. However it doesn't really make much difference.
Has any one had it solved?

Checking oil level when there is a mechanical fault within an engine is like checking your shoe laces when you’ve got a broken leg... it won’t resolve the problem one bit

You really need to identify the root cause, which in your case should start with checking oil pressure when cold and when hot. Then if pressure is low when cold and when hot, playing a little with oil viscosity to cater for oil pressure loss via worn bearings may help (for a while)... but ultimately the worn components need to also be addressed before catastrophic failure

I find @VTS5 tensioner pictures interesting in that the dark oil band was built up on the exposed part of the tensioner plunger over considerable time during “normal” operation. Then there are two other distinct and progressively lighter bands that indicate the second and third “extensions” occured progressively quicker. What causes the tensioner to extend further and further is the chain stretches which it seems to do in spurts, probably before it breaks and you need a new engine...

I’d ask your mechanic son for “mates rates“ on fixing your tensioner using quality factory parts sooner rather than later else you may regret it

 

[185OSS]

Checking oil level when there is a mechanical fault within an engine is like checking your shoe laces when you’ve got a broken leg... it won’t resolve the problem one bit

You really need to identify the root cause, which in your case should start with checking oil pressure when cold and when hot. Then if pressure is low when cold and when hot, playing a little with oil viscosity to cater for oil pressure loss via worn bearings may help (for a while)... but ultimately the worn components need to also be addressed before catastrophic failure

I find @VTS5 tensioner pictures interesting in that the dark oil band was built up on the exposed part of the tensioner plunger over considerable time during “normal” operation. Then there are two other distinct and progressively lighter bands that indicate the second and third “extensions” occured progressively quicker. What causes the tensioner to extend further and further is the chain stretches which it seems to do in spurts, probably before it breaks and you need a new engine...

I’d ask your mechanic son for “mates rates“ on fixing your tensioner using quality factory parts sooner rather than later else you may regret it

Thanks Skylarking for you informative post.
I will have my car checked and get a quote. Or may have to sell my car

 

[hookalaya]

I've got same problem VE 3.6 alloytec.. mine just sounds tappy for 1 or 2 secs then it sounds normal. Definitely not that timing chain rubbing on metal sound..
What I've been told is the oil pickup pipe has a rubber grommet on it and when that gets old it can't hold pressure after engine turns off so all the oil drains back into the sump then everytime u start it especially when its cold start it sounds like there's no oil in the motor when there clearly is oil.. or it can be blocked or partially blocked oil pick up pipe or rooted oil pump will do same thing. Test it with an external oil pressure guage if its at spec when cold and hot its probs just a poxy oil pump pick up pipe rubber o ring seal...? $2.00 part
I'm going to do mine asap hopefully its just the o ring ..but a few ppl have had this happen to them on this forum and 1 guy said the o ring fixed his after he spent heaps on timing chains and other parts that weren't needed but o ring fixed it.. worth trying this first as its cheapest option and fairly easy to do

 

[1997 VT Calais Series 1]

My 2009 VE V6 SIDI Commodore has done 300,000 klms and is also making that horrible rattle noise every cold start up for the last few years. My mechanic son reckons it's the timing chain tensioner, which would be very expensive to replace. I keep a check on the oil level to make sure it's full. However it doesn't really make much difference.
Has any one had it solved?

$1000 to $1500 is the going price "Do Not Pay Anymore Than This" This includes parts and labour.
There is a lot to remove before you or they get access to the timing chain,.
4 to 6 hours in labour (that's apart and back together) should be no more than this.

 

[Scobescide]

I have a VE Commodore(155k), and with cold starts I always had a god awful rattling noise during start-up (almost to the point of stalling). I thought oil suction may have been an issue and that the tensioners weren't getting enough descent oil pressure early in the crank/ignition phase of starting so I did some research and considered removing the oil pan to check the suction screen and suction pipe O-ring. Suction pipe screen mesh was clean and when I checked the O-ring seal (which was in good condition), I found the seal did not sit proud enough to create a perfect seal against the crankcase suction port. My guess was that under cold conditions, the O-ring shrunk a bit and caused the oil pump to pull air at the suction pipe more easily than against the cold oil in the oil pan, aerating the oil that should be pressurising the chain tensioners.

long story short is I replaced the seal, verified it was sitting higher than before, creating a better cold temperature seal between the suction pipe and crank case. Did a cold engine start this morning and was very pleased with the results.

 

[hookalaya]

I have a VE Commodore(155k), and with cold starts I always had a god awful rattling noise during start-up (almost to the point of stalling). I thought oil suction may have been an issue and that the tensioners weren't getting enough descent oil pressure early in the crank/ignition phase of starting so I did some research and considered removing the oil pan to check the suction screen and suction pipe O-ring. Suction pipe screen mesh was clean and when I checked the O-ring seal (which was in good condition), I found the seal did not sit proud enough to create a perfect seal against the crankcase suction port. My guess was that under cold conditions, the O-ring shrunk a bit and caused the oil pump to pull air at the suction pipe more easily than against the cold oil in the oil pan, aerating the oil that should be pressurising the chain tensioners.

long story short is I replaced the seal, verified it was sitting higher than before, creating a better cold temperature seal between the suction pipe and crank case. Did a cold engine start this morning and was very pleased with the results.

Good stuff my VE had the exact same problem I pulled the valve covers off and couldn't believe the amount of sludge and carbon build up. So dropped the sump oil pick up was blocked big time rubber seal was hard as nails and shrunken. So its definitely a stock problem that happens over time. I'm rebuilding my lt7 from the ground up Mace pistons Mace performance cams new Mace valves roller rockers lifters etc. Spent a few k already but can't wait to turn the key.

 

[greenacc]

You guys are giving me ideas on what I can do to keep occupied while Sydney is in lockdown..