SimonG

Gs450H Vvt-I Belt Replacement

Recommended Posts

Hi guys

As I've mentioned in a previous post on this forum my GS450h developed an engine rattle/tap when cold some time ago and I've had little success is getting the issue diagnosed and repaired.

However, the car went in for a recall this week for something unrelated and I asked them to look at the tap/rattle issue again in the hop that the extended warranty I have on the car would cover anything they find.

The good news is that they did trace the issue to a worn VVT-I belt but they say the extended warranty does cover this as its wear & tear (sigh 😒) but that the issue will not get any worse and is not something to worry about.

I asked about the cost of getting this replace outside of warranty and was told it was a massive job with labour alone costing >£1k

I would assume a worn valve-timing belt is a critical part and if it failed then the result would be significant. Also, does Lexus replace these belts at some point as part of the normal service schedule? The cars done 120k miles with full Lexus service history.

Many thanks in advance

Cheers

Simon G

Share this post


Link to post
Share on other sites
 

There are no belts on this engine they use timing chains so I assume one of the auxillary chains has stretched which I find strange as they are both short with no tensioners.

Another backwards step from where 2 intermeshed gears did the same job without problems.

Share this post


Link to post
Share on other sites

Does seem a bit odd - I think I'll ask the to re-confirm in an email

Share this post


Link to post
Share on other sites

are you sure they are not talking about the VT belt ie transmission drive belt (if there is one)

les

Share this post


Link to post
Share on other sites

Hi Guys

I don't have an update on this as such as I've chased Lexus Poole for a formal description of what is causing this noise and to date that have not provided anything.

However, despite Lexus saying the issue would not cause any problems or get any worse the sound is definitely getting much worse to the point where people are starting to comment or give me concerned looks at the noise emanating from the engine.

I'm starting to wonder if the noise is either the timing chain (or VVTi chain?) rattling or a bearing staring to fail.

Either way I need to get the dealer to look at the issue again but unfortunately I have meeting all over the country this week that I can't move and I'm likely to clock up 1k miles so I'm really hoping something doesn't give out and cause major damage.

If it is the timing/VVTi chain or a bearing would this normally be covered under the extended warranty I took out last year or would Lexus simply say it's wear and tear (125k miles) and not covered?

Cheers

Simon G

Share this post


Link to post
Share on other sites

given that the timing chain doesn't have a scheduled change interval I'd say that any work required shouldn't be treated as wear & tear however you would need to look in the T&Cs to see exactly what is/isn't covered.

Share this post


Link to post
Share on other sites

Hi all sounds to me like vvti controller rattling.i have changed these when I worked at main dealers on is200 and gs300 v6 model.only the intake controllers need changing. You can change these without removing the front timing cover but it is an involved job though

Share this post


Link to post
Share on other sites

given that the timing chain doesn't have a scheduled change interval I'd say that any work required shouldn't be treated as wear & tear however you would need to look in the T&Cs to see exactly what is/isn't covered.

What would cause it to make such a noise though ....... If it's stretched the I would have expected it to happen very gradually but this issue started just a couple of months ago (it not the same noise as the engine rattle I have when cold that's been there for 2 yrs).

Also, doesn't the chain have tensioners to prevent this sort of thing, so if they've failed would that still be wear and tear?

Many thanks

Simon G

Share this post


Link to post
Share on other sites

Hi Simon the noise was from the vvti controllers themselves not the chain. We just used to change the controllers. The noise was a loud rattle on initial cold start up for about 2 to 3 seconds does that sound the same as you have? As I said you can change them by taking out the camshafts without removing the timing chain front cover

Share this post


Link to post
Share on other sites

Sorry meant to say is250 damn that predictive text!!

I keep using the next door neighbours wife..... sorry wifi :)

Share this post


Link to post
Share on other sites

Like earlier engines there are additional VVTI oil filters on this engine, one on each bank.

I seem to remember some GS300 engines suffering with an initial top end rattle because the filter has become clogged so preventing a good oil flow to the VVTI actuator on cold starting.

IIRC periodic replacement of these filters are not part of the service programme but I am now wondering if these could be the cause of the noise you have.

At around a fiver each it may be worth changing them.

Part number is the same for both banks 15678-46020

Share this post


Link to post
Share on other sites

Hi Guys

The noise is constant ant not just at start up ..... Although it did seen to start this way.

At the moment the engine sounds has a very metallic rattle/scraping noise that seems do come from the top of the engine and is now there whenever the engine kicks in regardless of whether its just been started or has been running several hours on a long trip - Does not sound healthy at all.

Oil level is fine do I know it's not that and the oil is clear even though it's done over 9k since last service.

The noise has become much more pronounced over the past 1k miles even though Lexus said it would not get worse - my experience if Lexus Poole over the past 2 yrs has not been good so I don't really trust their diagnosis and I'm considering paying an Indy to have a look - can anyone recommend a good Indy in Dorset?

Cheers

Simon G

Share this post


Link to post
Share on other sites

Hi guys

I've uploaded a clip to YouTube so you can hear the noise the engines making - doesn't sound healthy and guess Lexus' comment that it's nothing to be concerned about May not be reliable.

http://youtu.be/wP-9R3SC_IU

Any thoughts on what would cause this noise?

Cheers

Simon G

Share this post


Link to post
Share on other sites

Do you have any other dealers near you?

Share this post


Link to post
Share on other sites

Hi Simon has it had the valve spring recall done? Just wondered if it was a slight miss fire that was causing hybrid transmission to rattle I have had this before on Rx400h and Gs450h when they had slight miss fire sometimes with no engine light on either

Share this post


Link to post
Share on other sites

Hi Dave

Yes, apparently is had had the valve spring fix carried out as I checked this some time ago when I started getting a rattle on start and valve chatter at low speeds until the engine reached operating temp.

The current noise is different to that noise (which is still there) and sounds like something metallic is loose in the engine.

Doesn't seem to affect performance or MPG but is getting worse.

If it is the timing belt or tensioner failing then I hope the extended warranty covers this - I know timing "belts" are not covered but a belt is a service item that is replaced as part of the normal service schedule, but the chain is supposed to last the life of the car and has no service replacement.

I'm taking it in to Lexus on Friday and I've emailed them that video clip - I'll let you know the outcome.

Cheers

Simon G

Share this post


Link to post
Share on other sites

Cheers Simon I would be interested to know what's causing the noise because apart from the valve springs breaking (which I did have one once) not really come across any issues when I was at main dealers with that engine

Share this post


Link to post
Share on other sites

Will do Dave

My engine sounds like a diesel at the moment and has had "tapping" issues for over a year that the Lexus dealer has never Been able to resolve - but I have to admit I'm not very confident in their abilities to diagnose based on my experience to date :/

They are charging me to look at the car on Friday and as this is a repeat visit for the same issue I hope they can actually confirm what the issues is as I felt fobbed off last time.

Share this post


Link to post
Share on other sites

It's a shame that you are not closer to me (I'm in Sheffield!!) would like to have look at

Share this post


Link to post
Share on other sites

Well, I've made some progress with this.

The noise in the video I uploaded has been diagnosed as the water pump bearing about to fail - luckily this is covered by the extended warranty.

However, the dealer still says tapping noise under light acceleration (different noise to that in the video) is apparently caused by the VVTi belt and not covered by warranty unless it fails completely - I had hoped that replacing the water pump may have given them an opportunity to replace whatever is making the noise with the VVTi belt but apparently not - that would require a major engine strip whereas the water pump only needs a couple of hours I the w/shop.

Still, I'm pleased that the water pump is being replaced under warranty and diagnosed before it failed completely

Cheers

Simon G

Share this post


Link to post
Share on other sites

At least they found something but I don't understand this vvti belt thing as engine is chain driven only belt on it is the aux belt

Share this post


Link to post
Share on other sites

I agree - they're not giving me too much info on this so I'm going to continue pushing as I'd like to had a formal description of the issue in writing ...... If only to put any future owners mind at ease when I sell the car.

From the investigations I've done (and I know nothing about cars) there looks to be a VVTi chain, not a belt, that has tensioner - so I would have assumed that the most likely problem would be something to do with the tensioner considering the noise appeared suddenly one day.

I'll see if it's any better after they replace the water pump and if not I'll definitely get a 2nd opinion.

Share this post


Link to post
Share on other sites

If remember correctly there are 3 chains 1 main one and 2 smaller ones on the cam each with their own tensioner. I will get in touch with one of techs at lexus main dealer I used to work at that I keep in touch with and run it past him but I've not come across any problems with chains on that engine but he may know different. I will let you know what he says

Share this post


Link to post
Share on other sites

Yes there are three chains.

There have been TSBs issued for that engine in the US for noisy startup and the fix is replacement gears on the intake camshafts. However this appears to be different, but almost certainly related to one of the chains/tensioners/gears.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now