Cam Chain Wear

ruutastic · November 26, 2017

Hi guys-

I am new to the forum though have owned my IS-F for 3 years now, I wanted to ask your advice on whether anyone has experienced cam chain stretch/ tensioner wear on their ISF yet?

Im running a 2008 with just shy of 110k miles and the car has been throwing cam position sensor faults that bank 2 is running retarded and in honestly especially when hot the top end sounds like a bag of bolts, I am obviously concerned with whether anyone has seen this before? Having spoken to my local dealer, they have never heard of any of this work being carried out as yet, but the quote was an eye watering 6k to get the chains and tensioners replaced which was a bit of a kick in the teeth- I had thought that lexus went to cam chains to stop the servicing of belts at around 90k.

Any advice would be kindly appreciated.

Many thanks

Andy

Big Rat · November 26, 2017

@ruutastic Hi Andy welcome to the forum, I have never heard of a car on here with an issue as described and many use there car to there full potential with some still being tracked with a100k plus miles, I'm sorry you have a problem now with yours.

Whats the history of the car do you know her past I run a list of ISF'S that is now 80% complete of the cars that remain.

Have you got the original reg number I'd be happy to look to see if the past use may help to make a decision for you as to whether to repair or not.

Big Rat

Northern isf · November 26, 2017

That is a ridiculous quote I've seen whole engines going for 4k, I'm pretty sure there'll be an Indy Lexus garage which would be a lot less than that it'll just be a case of finding one that's confident in working on this engine.

08ISF · November 27, 2017

Just a thought, these engines are VVTi (variable cam timing). As I understand it there is some sort of actuator on each camshaft which varies the cam timing according to driving conditions. Has the possibility of this being worn out or broken been discounted? It might explain the " bag of bolts" noise. Bearing in mind how robust these engines are, to my mind, the actuator or a sensor fault is more likely than stretched timing chains/loose tensioners. If it is the actuator it won't be cheap because no doubt it is lovingly hand made from a very rare alloy, but it can't be £6K.

As far as the quote is concerned IMO Lexus are taking the p***. I would take it to another Lexus dealer or an indy. Anybody in the North London/Herts area able to recommend one?

Let us all know how this pans out.

Peter P18 · November 27, 2017

Hi Andy,

First I've come across for this (that's across both UK and US forums) particular fault.

I'd 100% be looking for a second opinion if I was you. I'd also look to source a replacement engine if those costs are accurate. There were some for sale in the States which you could probably buy, import and pay all the VAT/duty/tax etc, and still come in cheaper than the local dealer quote!

Other option would be to ask if Lee Perryman over at SRD in West Sussex is willing to work on it for you? Lee recently completed a supercharger installation on my car, so is the closest we probably have to an independent specialist on these rare cars.

You would need to appreciate this would be their first engine strip down, but at £60+VAT an hour, they will easily come in under main stealer prices.....

I'd have a vested interest in this, as I may one day look to go down the forged/low compression pistons route.

You can get it trailered over to SRD easily enough, think there is a guy who can do it for you with a proper enclosed trailer etc if you want me to ask Lee?

Whatever you decide, best of luck, and sorry to start here on such a low!

All the best,

Pete

Big Rat · November 27, 2017

@ruutastic Andy as @Peter P18 suggestion if you go that route I’ve found two cars for you that may be suitable.........

mike m · November 27, 2017

4 hours ago, 08ISF said:

Just a thought, these engines are VVTi (variable cam timing). As I understand it there is some sort of actuator on each camshaft which varies the cam timing according to driving conditions. Has the possibility of this being worn out or broken been discounted? It might explain the " bag of bolts" noise. Bearing in mind how robust these engines are, to my mind, the actuator or a sensor fault is more likely than stretched timing chains/loose tensioners. If it is the actuator it won't be cheap because no doubt it is lovingly hand made from a very rare alloy, but it can't be £6K.

As far as the quote is concerned IMO Lexus are taking the p***. I would take it to another Lexus dealer or an indy. Anybody in the North London/Herts area able to recommend one?

Let us all know how this pans out.

Theres probably a vvti controller attached to the cam sprocket on each head. I know from previous experience of a failed vvti controller on another Toyota that it causes a separate fault code p1349 and causes the engine to judder at the vvti switching point as if it's going on/off the power repeatedly. Only in light throttle.

I think things like poor oil, lack of oil changes etc causes them to fail along with the chains but there are filters for the oil control valves that can get clogged giving vvti issues.

@ruutastic Ive heard of these engines sounding like a bag of bolts before. Certainly seen a few vids about it on the tube and I think the oil scavenge pump gets blamed.

I know mine taps away sometimes. Good luck getting it sussed.

ruutastic · December 5, 2017

so the car has been in with lexus main dealer for diagnosis because i have spoken to 5 indies who all have told me they absolutely dont want this work, even the guy at lexus service dept that has dealt with this car for years sat me down and said they were scared when i brought it in.

essentially told them all the issues, the code being tripped is P0012 - camshaft bank A running too retarded. I was hopeful that this may have been the controllers playing up, though having had the diagnosis back today, both controllers appear to be working fine. The lexus master tech has said that there is a little bit of a chattering coming from the engine when hot, and because of this he wants to change the small chain that links the cams on bank a. £1600 + vat for this, which for me was swallowable and i didnt really have a problem when they dropped this on me until they said that they werent sure and that they will not be covering the cost if it is the wrong diagnosis.

So essentially, lexus want me to throw the best part of 2k at this car without knowing if it is actually going to solve the problem, and it will be at my cost if it isnt the fault.

All your thoughts are much appreciated. Im tempted to buy one of these spare engines and get it worked in.

Peter P18 · December 5, 2017

Yikes!

I’d personally fork out the cost to get the car over to Lee Perryman and his team at SRD in West Sussex.....

Still think they’d come in better in the long run than the gamble you’d be taking with the main stealer!

It’s ultimately your decision, but the lack of belief and uncertainty mixed with their higher costs would worry me....

Best of luck whatever you decide.

December 5, 2017

If it was the chain.... Would it not exhibit the symptoms hot and cold? What changes when the engine is hot?

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Northern isf · December 5, 2017

That is some predicament to be in, me personally I would want them to cover the cost if it is the wrong diagnosis as like you say it's throwing money away if it turns out to be more serious it's collateral you could use for a new engine. Saying this though it does seem a reasonable explanation that the Lexus tech has come up with, metal does expand when warm so that could explain the chattering on the chain but it's all "coulds" I feel bad for you I really do there's nothing worse than been in situations like this I've been there a fair few times and almost smashed a few cars up in frustration.

Flytvr · December 5, 2017

I'd be tempted to trade it in.

Northern isf · December 5, 2017

12 minutes ago, Flytvr said:

I'd be tempted to trade it in.

That's not a bad option, would certainly save on potentially wasting some serious amounts of cash

steve2006 · December 5, 2017

It would be interesting to see the service history on this car particularly oil and filter changes, cam chain wear and stretch is commonly due to a poor service regime and/or incorrect oil use.

Another expense is a worn chain will also damage the spockets so more expense.

Spacewagon52 · December 5, 2017

That is a scenario we all dread. You are effectively writing off the car after 3 years ownership. A horrible situation. My preference would be to take a chance with SRD in West Sussex. The other alternative is a replacement engine from a breakers. You will need to weigh up the £££££ lost and possibly ££££ spent with no joy. I feel for you too.

One major advantage (not applicable to the fantastic ISF) of owning a cheaper car is that you can say goodbye without breaking the bank.

Best of luck - keep us informed what you decide.

mike m · December 5, 2017

Doesn't sound like this does it?

Some info in the comments about it.

Big Rat · December 5, 2017

@ruutasticAndrew sorry again for your predicament, I had a problem only recently with my Works Transit a bill for 3k + vat and it was misdiagnosed, had from new 40k miles and it did the same.

Bit the bullet and got shot and bought a new one, go the blanket of a warranty for 5 years.

End of the day your choice but as others have said get rid if you want another there’s loads for sale at the moment at the stealers at least you will get a warranty for a year or two.

Big Rat

Flytvr · December 5, 2017

Try and get a Lexus warranty on it.

NothernDan · December 6, 2017

+1 on the trade in route. Tell em you love it but you want one in a different colour.

So sorry to hear you are having these issues mate. Had a similar situation with my old 335i. Needed new turbos and injectors so with labour it was going to be six grand and change. Ouch.

Two days later I was hit in a queue of stationary traffic by a Ford Iveco going at full tilt. Problem solved. Only downside was a bit of whiplash.

I'd get it traded in. Good luck whichever route you choose though.

December 6, 2017

16 hours ago, Northern isf said:

That is some predicament to be in, me personally I would want them to cover the cost if it is the wrong diagnosis as like you say it's throwing money away if it turns out to be more serious it's collateral you could use for a new engine. Saying this though it does seem a reasonable explanation that the Lexus tech has come up with, metal does expand when warm so that could explain the chattering on the chain but it's all "coulds" I feel bad for you I really do there's nothing worse than been in situations like this I've been there a fair few times and almost smashed a few cars up in frustration.

7.2 x 10^-6_{^{is the expansion rate of steel.}}

So a 100cm steel chain would lengthen by 0.0576mm for an 80 degree increase in temp. (If I got the maths right).

80 degree rise in temp was an assumption as I can't measure the difference hot to cold.

Clearly it's best to leave the speculation to the experts but it's handy to have questions to ask - if they can't explain it to you then they don't fully understand it either.

Trade in is the easy way out of this as others have said.

ruutastic · December 6, 2017

All things considered with lexus, the tensioner does seem like the likely cause, And as someone with history working with (much simpler) engines, I had no problems agreeing with the lexus tech that this is a likely symptom, however I just hate the idea of chasing a problem around this engine not knowing whether it will be a problem again, also if bank 1 has this issue.. how long before bank 2 shows the same issue!

I spoke to Lee at srd this morning, And I realised that love this car and realistically the only thing I would chop it in for realistically is a gsf... and i think thay might give the mrs a brain aneurysm, so I think theres only one way forward really, engine swap it is for me! So I'm on the lookout for an engine, any help from you guys on this front would be much appreciated.... I've seen the ads for the scrapped vehicles and talked to them, the 2010 already has it's engine sold and the 2008 is certainly expensive so I've got to keep my mind open and hope that something will come up, If anyone knows of any engines collecting dust somewhere im happy to give it a loving home where it will be pampered!!

Honestly thanks for all your help so far and hopefully in advance for the help going forward

Andy

NothernDan · December 8, 2017

Surely the cost of a new engine and fitting exceeds the loss you'd make on a trade to another ISF?

I'd try and leave any emotional attachment out of it and look for the best financial route or this could be very costly.

I obviously don't know the costs for you but I'd make a cost comparison of engine swap Vs trade in and see what works out best for your wallet.

Jgtcracer · December 8, 2017

9 hours ago, NothernDan said:

Surely the cost of a new engine and fitting exceeds the loss you'd make on a trade to another ISF?

I'd try and leave any emotional attachment out of it and look for the best financial route or this could be very costly.

I obviously don't know the costs for you but I'd make a cost comparison of engine swap Vs trade in and see what works out best for your wallet.

Agreed, just get it traded in. Any emotional attachment you have will soon go once you get a new car.

Possibly time to upgrade to an RCF or GSF?? Lol