Whenever the engine is started when it's cold it makes a horrible rattle/grinding sound. On a really cold day it will do it for 2 minutes, some days it rattles for 5 seconds, on warm days its fine. It sounds like its coming from the left side of the engine, around the timing belt, but i cant be sure. I've uploaded a video here (http://www.youtube.com/watch?v=n-fWtArqdC8) (turn ur volume down), there are a couple of other videos with the exact same thing, and one guy said it was the timing belt tensioner. Can anyone confirm if that may be the problem, and how much it should cost to get fixed? It was doing it before and after the timing belt was changed and I wouldn't back myself to have a go at it. Any help would be much appreciated

If you stop the engine then restart it & find the rattle is gone chances are it's the timing belt tensioner.

Cheers

Not a sound I've heard from a 3.5 before - from a tractor, yes- try taking the ancillary belts off and see if the noise is still there, then you will know that its a cam belt problem. If the engine sounds good without those belts on, check the exterior idlers, alternator, air con and steering pump for roughness when you turn them by hand. (engine off at this point)

You haven't run the engine out of oil at any stage have you? It's too loud to be a cam tensioner noise, might be a lot more serious. Might just be one of the cam belt idler bearings though, hopefully. Sounds like the car isn't safe to drive like that. (Safe for the car, that is. You may be doing a lot of harm to the engine using it as it is.)

You can't really be sure what causes the noise, but some exploratory surgery to open the patient is called for.

I have the same problem on my '03 TL Magna ES, which has been diagnosed by Madmagna (Mal from Mitsfix) as a dodgy timing belt tensioner.

Here's how to diagnose it as per Mal's instructions:

1. Leave the car overnight to get really cold
2. Disconnect the cam pulse sensor (it's the plug just off the to side of the plenum chamber and above your timing belt cover. It's actually mounted to the plenum chamber I believe.
3. Crank the engine for 10 seconds (it will fail to start)
4. Reconnect the cam pulse sensor
5. Start the car. If it does not rattle now, the problem is your timing belt tensioner.

Mal has said that the tensioner is hydraulic. I am unsure if this means it is fed by oil pressure from the engine or it is just a spring with a hydraulic valve that limits its speed of travel. Either way they get gummed up and can need replacing. I should personally have done mine already by now, but with three kids and both me and the wife working, it's a feckin' pain in the ass dropping *either* of our cars off anywhere.

It's too loud to be a cam tensioner noise

I disagree - mine can be quite loud depending how much the tensioner has backed off.

I disagree - mine can be quite loud depending how much the tensioner has backed off.


OK. I will know what it is when mine starts to make that noise. lol Easy fix if that is all it is.

"I am unsure if this means it is fed by oil pressure from the engine or it is just a spring with a hydraulic valve that limits its speed of travel."

SECOND option is correct.

It's too loud to be a cam tensioner noise.

Good to see that our forum technical expert has now spoken, seems you have destroyed the engine and it is time you get it replaced, all this off a vid hosted on an internet server, well done agian ......

Now, back to the OP, as you are in vic, can I suggest you bring the car here, leave it overnight or at least long enough so I can hear in person the sound? I have heard them bad like that when the belt has been stretched almost beyond its limits not long before the belt has broken and then all bad stuff happens lol...Is very hard to hear with all the echo in the vid but my money is on a combination of the tensioner and the fact I would say the belt is very old and past its service interval.

Kaldek, I think was yourself I got the handbrake parts for lol, they are still here mate :) and I can do your tensioner same day as well lol

Good to see that our forum technical expert has now spoken, seems you have destroyed the engine and it is time you get it replaced, all this off a vid hosted on an internet server, well done agian ......


Last time I heard that noise was on a Holden 202 motor and turned out to be mains/big ends. I'm not an expert like you (not even a novice, as you said before in a PM), so I'm receptive to correction. I don't think I mentioned he rooted his motor and needed a new one? I did say it "might be a lot more serious". Bit of a stretch there, Malcolm.

At least you agree its not a good idea to keep driving it like that. lol

Personally I would not even start an engine that sounded like that, unless purely for diagnostic reasons. I may be wrong, the OP does state belt has been done and that in itself scares me if this noise is there after someone has supposidly done a new belt, the fact that this mechanic left that tensioner on does not really provide much assurance of workmanship either to be honest

I have the same problem on my '03 TL Magna ES, which has been diagnosed by Madmagna (Mal from Mitsfix) as a dodgy timing belt tensioner.

Here's how to diagnose it as per Mal's instructions:

1. Leave the car overnight to get really cold
2. Disconnect the cam pulse sensor (it's the plug just off the to side of the plenum chamber and above your timing belt cover. It's actually mounted to the plenum chamber I believe.
3. Crank the engine for 10 seconds (it will fail to start)
4. Reconnect the cam pulse sensor
5. Start the car. If it does not rattle now, the problem is your timing belt tensioner.

Mal has said that the tensioner is hydraulic. I am unsure if this means it is fed by oil pressure from the engine or it is just a spring with a hydraulic valve that limits its speed of travel. Either way they get gummed up and can need replacing. I should personally have done mine already by now, but with three kids and both me and the wife working, it's a feckin' pain in the ass dropping *either* of our cars off anywhere.
I just followed these instructions and it started without the rattle (and the car has been left overnight, still cold). So it should definitely be the timing belt tensioner?

Kaldek, I think was yourself I got the handbrake parts for lol, they are still here mate :) and I can do your tensioner same day as well lol

*GULP* Yeah it's me. I've been fretting about you reminding me that I've been a sh*t customer for a while! OK alright I'll bite the bullet and give you a call this coming week.

I just followed these instructions and it started without the rattle (and the car has been left overnight, still cold). So it should definitely be the timing belt tensioner?

Sounds like it; give Mal a call ASAP and get him to look at it, as he may be able to fix it the quick way (however yours rattles for a lot longer than mine so maybe your belt is also a problem). Hell you'll probably see my car there getting the same job done. :-)

I'll let Mal talk in more detail about the quick way versus the long way of replacing a tensioner, as I'll be buggered if I can remember what he said about it.

Also, I should really point out that Mal's diagnostic procedure was - in my case at least - specifically to confirm that the problem wasn't the well-known rusted exhaust rattle. His procedure didn't have anything to do with diagnosing the severity of the problem!

Personally I would not even start an engine that sounded like that, unless purely for diagnostic reasons. I may be wrong, the OP does state belt has been done and that in itself scares me if this noise is there after someone has supposidly done a new belt, the fact that this mechanic left that tensioner on does not really provide much assurance of workmanship either to be honest
Mine's the same mate - belt replaced at a tick over 100,000km (before I bought the car). Seems like it's fashionable to do a crap job on Magna timing belts at lots of places!!

Of course this where I drop off the car and you tell me the belt was never replaced. :-/

Ok folks, Mal (Madmagna) fixed my tensioner yesterday. Apparently it looks like the last guy who changed the timing belt tightened it up way too much. Subsequently it stretched the belt some, and combined with a sticky tensioner it caused the cold start rattle. Mal says he's not too concerned about the belt being a bit stretched - he has adjusted and tightened everything accordingly. The car certainly did not rattle this morning when I started it.

He was going to fix my stuffed handbrake at the same time, but I seem to have lost the lock nut from the mags. :-/