LS460 Engine code P0017 pending

[Peter67]

Hi. I’ve been running this car for 4 years and very occasionally I had a loss of power on acceleration when the car was under load such as a slight up hill etc. I had it checked out and my mechanics could not really find anything definitive, no codes etc. About 4 months ago it became much more frequent and although there were still no codes I left it with my mechanics for 1 week and they could not fault it at all.  Note the car now has 275,000Km (170,000 miles) up.

Based on internet research I suspected a dodgy camshaft Oil control solenoid valve. I replaced both of these myself and the car was immediately perfect. It drove like a new car with super power and engine response I change the oil regularly every 15000km with Mobil 1 0w 30 and use a Lexus oil filter so I was surprised because these OCVs are known to be an issue with extended oil change interval and dirty oil.

Anyway, 4 months passed without incident then the problem has come back. Exactly like before. The car occasionally (2 or 3 times a week) bogs down when applying power from low speed. The power then suddenly comes in like a turbo. Also When cruising at 60-80kph the engine will “flutter” and run rough and then after a while its ok. The issue will disappear for several days. To me it feels like a valve timing issue / cam phasing issue and because its intermittent I don’t think the timing chain could be in trouble (please not). I normally connect an Autolink Al519 OBD code reader to see whats going on but yesterday I connected up my Techstream and I discovered for the first time a pending code of P0017 which was related to the last journey and has a description “Crankshaft Position - camshaft position correlation (Bank 1 Sensor B)”. 

I took out both VVT camshaft sensors from Bank 1 and inspected them and measured resistance between the pins. I am not sure what value to look for but they were both the same resistance so they appear ok. I checked the wiring and connections and all seems ok. That leaves the camshaft timing / vvt phasing.

The car drove well today for 200km with no loss of power or engine bogging down.

Question 1 - Is sensor B the exhaust or inlet camshaft? I think its the exhaust.

Question 2 - Does the camshaft oil control solenoid valve on the LS460 have a mesh filter like other Lexus vehicles like the IS? I looked on engine diagrams and parts lists and it appears that it does seem to have a filter but that its inside the rocker cover in a gallery. If it was meant to be accessible for cleaning like the IS then you would expect it to be easily accessible ?

Question 3 - Could a blockage to the OCV result in a P0017 code?

Question 4 - Could a camshaft phaser be stuck or sticking in position and could this result in a P0017 code?

Question 5 - If it does come down to a full timing chain replacement has anybody had this done? And is it something a good tech / mechanic can manage without any specialist Lexus tooling? I assume all chains would need replacing.

Question 6 - Any idea on the number of labour hours to repalce the timing chains and tensioner?

Question 7 - Does anybody have any other suggestions? 

Regards

Peter

 

 

[messi]

It's the crankshaft sensor, not camshaft but I'm not sure if these 2 are the same thing but it is the crankshaft sensor

[ColinBarber]

8 hours ago, messi said:

It's the crankshaft sensor, not camshaft but I'm not sure if these 2 are the same thing but it is the crankshaft sensor

It is crankshaft to camshaft correlation, often a timing issue but could be one of the sensors.

[Peter67]

Thanks. As the crankshaft sensor is just one device and its comparing / correlating to the 4 x Camshaft vvt sensors and the 1 x camshaft position sensor I would have thought if it was the crankshaft sensor at fault that it would throw different codes and also conflict with more of the 5 x camshaft sensors than just the one. I would expect to see P0017 and P0018 at the same time surely?

As I said I pulled the sensors and tested them for resistance but not a dynamic test. Do people think its worth sticking in a new sensor or should I just go and get it thoroughly checked for timing settings and various sensor responses? When the loss of power is occurring It does feel that the vvt on just one bank is not engaging correctly. If one cam was not phasing correctly then in theory I would expect this sort of correlation code.

Regards

Peter

[ColinBarber]

I'm not convinced it is a sensor issue. I don't believe the timing is out so it would point towards VVTi issues. Most reports of this error have been for the 3.5 V6 engine and is either because the timing chain hasn't been re-installed correctly after engine work or VVTi/oil control valves.

I assume your oil level isn't low, and your Battery is good (as all sorts of error codes can occur if you aren't providing the vehicle electrics with a good 12v)?

[Peter67]

Oil level is perfect. It never budges on the dipstick

Battery is good, I replaced it last year.

Given the intermittent nature of the issue I would like to think the timing chain is unlikely to be at fault. There is no record of any work on this and the timing cover looks like it has never been touched. That sort of points back to a vvti issue as I have already replaced the 2 x oil control valves. I come back to the question about a vvti oil filter mesh located inside the rocker cover on the parts drawing. I wonder if this could be at fault.

[Newbie1]

Could it be an issue related to the intake VVTi that's controlled by an electric motor (as opposed to the solenoid activated exhaust VVTi)?

[steve2006]

I have mentioned this quite a few times but there are 2 micro filters, one on each bank which supply the oil to the VVTI system.

If these filters get partially blocked oil flow to the VVTI system will be reduced possibly giving problems like you have.

The filters are around $6.00 US each from dealers and fairly easy to replace on a DIY basis part number for both is 15678-46020 based on a LHD US specification model.

[Peter67]

Hi Steve. I did look for the VVT oil filters as I suspected they could be blocked. However on the LS460 unlike other Lexus models the VVT oil filter appears to be in a gallery accessible only with the rocker cover removed and this of course necessitates the dismantling of the High pressure cam driven fuel pump assembly as well as draining the fuel system. I don’t see any other way so I might have to do it. I do think the exhaust cam is more likely to be at fault because when i replaced the OCV it was perfect for a few months. This suggests the filter could be blocked or partially blocked.

Re Newbie1 posting this was something I considered the electric motor on the bank 1 intake side and its easy enough to replace  but expensive (part is €500 or so). I ran the Techstream tests on it and it seemed to respond ok as per the manual.

Regards

Peter