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GS450h rattle on start up & coolant issues


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I have a 2007 GS450h mileage around 122k.  I seem to be having a collection of issues and wondered if I could call on the knowledge in the forum please?

Around December it started leaking coolant, a look around found the water pump we replaced a just over 2 yrs prior was failing as the gasket (also replaced the stat), which wasn’t OEM, appeared to had turned to mush. Fitted an OEM pump and gasket and all seemed good for a few months. However when driving it steam started to appear. Found a fault pipe, resolved that, and it was fine again.  

 

A few weeks later OH comes back from work with yet more coolant issues and also reports an engine judder on start up. Drove ok, it was just the start up.   On cold start up it has a nasty ‘clatter’. Once it gets warmed up a little it starts to improve and sounds more ‘normal’. There is quite a radical shudder on start up. I had a go at interrogating it with an Autel machine (don’t have a TechStream) and  it seemed to generate the P3000 code (misfire?). Suspecting the coil packs, and knowing the plugs were slightly overdue anyway, we replaced those yesterday.  We also did an oil change and put 0W20 in & changed the oil feed banjo bolt filters, thinking this would also help keep the engine well lubricated. Sadly on start up there was no change. Just gone to get a video and it wouldn’t start on first attempt, but on second it did. Video attached hopefully. 

As an aside to this, we appear to still have coolant issues. I’ve replaced the thermostat when we did the w.pump the first time. Suspected it may have failed again, I tested it and it wasn’t opening until it reached around 97 degrees, so replaced that too. We are finding that occasionally the car doesn’t have warm air to come through but it appears to be random. 

 

I am concerned head gaskets/heads/block are potentially the cause. The coolant bottle was bubbling with air coming it to it (positive pressure - not heat) yesterday when I ran it for a brief period. The exhaust has white clouds when running - i won’t say steam or smoke as I don’t know which it is, and has a scent to it. It has been sat for a few weeks. The misfire (if that is what’s causing the juddering) could be as a result of the same suspicions, but no obvious water in the oil, or visa versa. I have read various things about other Lexus hybrids. One has mentioned the direct injection seals, another the EGR- but I don’t know the hybrid set up well enough to know if it even has an EGR. I’ve not been able to conduct a compression test yet, but was also curious as to whether this would be safe on a hybrid set up (didn’t want to inadvertently make things worse).   Any thoughts on potential causes/things to check would be appreciated. Happy to undertake head gasket replacements but if there is damage to the head/block then its game over.

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Make sure you bleed all the air from the cooling system. There is a number of relevant videos on Youtube. Having done that, should you still get coolant loss without any leaks and bubles in the expansion tank, you may have a head gasket issue. Cylinder heads can be repaired by profession engineering shops to perfection.

The rattling noise from the engine could be due to valve clearance adjustment or valve bucket wear.

 Inspect the valve buckets for a very small hole on their top, about the size of a needle. If you can see one then the valve clearance is self adjusting. In this case you need to replace the noisy buckets due to excessive wear.

If there are is no hole on the buckets then you can adjust the valve clearances by changing the shim of each valve out of specification. Some engines have the shims on the top, easily removable with the right tool, others have the shim on top of the valve and below the valve bucket, in which case you need to remove the camshaft to change it.

Chris.

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VVT-i hydraulic variable valve timing actuators not locking up when stopping and/or not holding oil at startup, or at least that's the first thing that comes to mind, given what it sounds like. The engine is also direct-injected, and it DOES run in "stratified combustion" mode while warming up the catalytic converters - i.e. right at the start. It makes a lean mixture with the port injectors and makes a "rich" pocket with the direct injectors in order to ignite it. This leads to higher exhaust gas temperatures and quicker catalytic converter lightoff.

https://toyota-club.net/files/faq/13-11-10_faq_gr-engine_eng.htm

I wouldn't run 0w20 in an engine that was originally specified for 5w30. I also probably just stirred up a hornet's nest.

Re: random warm air - get the t-stat open, put heater on HIGH, rev the engine for awhile in D-mode (easiest way to maintain ~2500-3000rpm), see if that helps.

Re: potential head gasket failure - check the cooling system for leaks (pressurize via a special cap & check whether it holds pressure, check where it leaks if it does - could be a cylinder), check the cylinders with a good borescope (clean usually means "vapour cleaning" i.e. eating water/coolant), check the old plugs for any indication of running lean/burning coolant/etc, check the system with a "block tester" (an "exhaust in the cooling system" test)... If it is, it won't be easy and/or cheap, but... IMO tear it down and do the whole thing proper.

@Mihanicos every engine in the 3rd gen GS lineup has hydraulic valve clearance adjusters.

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dont forget the radiator after 13 / 14 years of use there is a good chance

it may of been damaged by stones this could be where you are getting air

into the system

  • Thanks 1
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Indeed, my fault. I was thinking of the 2UR-GSE as the recent exception.

Re: radiator - mine did "blow up" (well, started leaking under high pressure) a few weeks ago, had to wait 10 days for a new OEM one. Car is 08/2008. About time 🙂

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  • 2 weeks later...

Had to wait a bit until I could look at the car, so started with the coolant pressure check today and seemingly at 10 & 15 psi it lost no pressure. Tried to start the car to do the emissions in the coolant check and it wouldn’t start. Whilst looking about I opened the oil cap and founded the dreaded mayonnaise.  It wasn’t there two weeks ago when I last looked and I’ve not taken the car out since but have run it up a bit so clearly things are progressing rapidly. Another coolant pressure check for longer concurred the coolant system has pressure loss - oh joy! 

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ADC217A1-C4E6-41B8-A5BB-E4C121D6D396.jpeg

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Well, that certainly looks like a failed head gasket.

It can't be too bad yet if it takes a while to lose that much pressure - perhaps it's worth trying Bar's Leaks Head Seal Blown Head Gasket repair. Might at least put things on a bit - or delay doing a proper head gaskets job.

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It would be a possibility but I have to move from one end of the country to the other soon so i would have to effect the repair sooner rather than later I think 

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Well I've started the tear down, think it will be a matter of replacing the  valves and headgaskets judging by the noises the engine made.  I can find guides to help with the valve replacements on the back of the 2010 SB, but no sign of any guidance on headgasket replacement. I'm not familiar with this engine so I'm keen I don't stuff it up, especially with 3 timing chains to argue with.  Does anyone have any helpful guidance/hints/tips/ links pls? I've done various searches but haven't turned up much for this engine yet - 2GR-FSE I believe.

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48 minutes ago, NickySB said:

Well I've started the tear down, think it will be a matter of replacing the  valves and headgaskets judging by the noises the engine made.  I can find guides to help with the valve replacements on the back of the 2010 SB, but no sign of any guidance on headgasket replacement. I'm not familiar with this engine so I'm keen I don't stuff it up, especially with 3 timing chains to argue with.  Does anyone have any helpful guidance/hints/tips/ links pls? I've done various searches but haven't turned up much for this engine yet - 2GR-FSE I believe.

 

19 minutes ago, 200h said:

Yea tried that one but wrong lump from the look of things 

47735247-6C36-4AB1-948A-A6DC527ED61C.jpeg

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You can get a repair manual from " emanualsonline " for about 30 euro.

They are very comprehensive and detailed. Follow the procedure outlined in the manual. Measure the various dimensions and clearances to determine which parts can be reused. Cleansiness inside and outside is the key to a perfect job. Do not worry about the timing chains, there are marks which should be aligned. Make certain you verify these marks before you begin dismantling, as a matter of principle and confirmation with the repair manual marks. Should you encounter any difficulties in the repairs, you can count on my help.

Chris

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2 hours ago, Mihanicos said:

You can get a repair manual from " emanualsonline " for about 30 euro.

They are very comprehensive and detailed. Follow the procedure outlined in the manual. Measure the various dimensions and clearances to determine which parts can be reused. Cleansiness inside and outside is the key to a perfect job. Do not worry about the timing chains, there are marks which should be aligned. Make certain you verify these marks before you begin dismantling, as a matter of principle and confirmation with the repair manual marks. Should you encounter any difficulties in the repairs, you can count on my help.

Chris

Thanks that’s very much appreciated 

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17 minutes ago, Sami Tilander said:

Remember also the official Lexus repair information at https://www.lexus-tech.eu/default.aspx . It costs only about £3 per hour, but already in one hour you can save lots of information to to your PC...

BR.Sami

 

Thank you, I had found the Toyota one but not the Lexus one - so that’s brilliant  cheers

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  • 1 month later...

So a mini update - been slowly working our way down to the heads, work and life permitting, and finally got there today- been concentrating on the passenger side as it seems to be the hardest ( on the hybrid anyway) and got pretty good confirmation of what’s been going on !

 

9D8A93DA-2265-4037-BF61-4D6A2692D5DE.jpeg

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40 minutes ago, NickySB said:

So a mini update - been slowly working our way down to the heads, work and life permitting, and finally got there today- been concentrating on the passenger side as it seems to be the hardest ( on the hybrid anyway) and got pretty good confirmation of what’s been going on !

 

9D8A93DA-2265-4037-BF61-4D6A2692D5DE.jpeg

I am not mechanically minded so I have no idea what is wrong but even I can tell it does not look good!

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15 minutes ago, Spacewagon52 said:

I am not mechanically minded so I have no idea what is wrong but even I can tell it does not look good!

🤣 - the head gasket has failed ( although I’ve not checked the head and the block yet) allowing the water around the cylinder to enter them- which is the opposite of what we want ☺️

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