LS430: Where is this oil coming from?

Antharro · May 31, 2020

Where is all this oil coming from?

For anyone not familiar with my LS430, it has oil problems, in that it smokes like a chimney when it wants to. In January (I think), it was diagnosed as either valve stem seals or piston rings - either way, beyond economical repair. And then the alternator started acting up. I was going to sell it, but then the lockdown happened and it's sat in my yard since.

I've started it a couple of times since then. On a couple of occasions it's smoked REALLY heavily, and on a couple of occasions it hasn't. Just like how it was when I was daily driving it.

After reading about the power steering pump leaking and causing power steering fluid to be pulled into the engine and causing smoke, and also dripping onto the alternator and causing alternator failure, I thought I'd have a look and see what I could find.

I removed the entire air intake system. I could immediately see the shine of oil on the bottom of the throttle body valve. This is what I could see when I looked inside. Pretty sure all that oil shouldn't be there, right?

I looked back through the various pipes and ductwork to see where the oil might be coming from. The pipe coming from the PCV valve was oily at both ends. I cleaned it and replaced it. There was another pipe coming from the other bank, which went into the underside of the thin box that feeds into the main air intake. This was also oily on both sides.

I also noticed that one of the pipes from the power steering pump was particularly grubby, and looking below it on the alternator, there was evidence that a liquid had leaked onto it and dried off (from the car being sat for a couple of months).

Lastly, the main air intake pipe had a small amount of oil residue in the "left" or "cold" side, and a larger amount on the side that connected with the valve.

I tried running the engine and putting my finger over the pipe which resulted in a slight build up of pressure, which released with a "pshhhhhhhh" sound when I removed my finger.

My theory is this - there's oil coming from the PCV valve, and from the pressure outlet pipe on the other side of the engine. There's probably also power steering fluid coming from the power steering pump. This builds up, gets sucked into the engine and burns off as nasty smelling blue/white smoke.

But I have no idea how to confirm this, and I have no idea how to fix it, so any help would be appreciated!

Lastly, what is the box I've pointed to in the pictures above, and what's inside it?

steve2006 · May 31, 2020

It appears to be excessive crank case pressure, if you remove the oil filler cap with the engine running can you feel it blowing out of there if you place your hand above the opening? You can normally also hear a “chuffing sound”. If you can this would suggest worn piston rings and a compression test would confirm this.

Could I ask what the mileage is on the engine?

At one time the crank case breather pipe went straight out to the atmosphere but with today’s emission requirements it has to be sent into the intake to be burnt with the fuel which is fine until the amount of oil causes excess smoke.

Another measure would be to fit an oil catch tank, this won’t stop the oil blow by problem but will reduce the amount entering the intake and being burnt.

Finally oil deposits on the PS pump area would suggest a leaking valve cover gasket, this unlike a smokey engine is a common failure on these engines.

runsgrateasanut · May 31, 2020

Is the Sump oil overfilled by any chance? You have written "always open valve" on what I assume is a photo of the PCV. It shouldn't be "always open" but spring loaded. Just a thought.

steve2006 · May 31, 2020

4 hours ago, runsgrateasanut said:

Is the Sump oil overfilled by any chance? You have written "always open valve" on what I assume is a photo of the PCV. It shouldn't be "always open" but spring loaded. Just a thought.

Good point regarding the oil level. The PCV may always be open though if there is constant over pressurisation of the crank case due to a worn engine, if the pressure wasn’t released it could start blowing seals out instead.

Antharro · June 1, 2020

Mileage is 150k. The car was looked after well by the first couple of owners (as far as I could tell from the history I could get from the dealers) but the owner who had it before me couldn't have cared less about it and maintenance was extremely lacking.

Oil level looks fine - it's just below the top level on the stick.

The valve I've marked as "always open" is not the PCV; that's on the other bank of the engine. This one seems to be putting out air all the time; it's not high volume but it's constant - if I put my finger on it and block it, I'll feel a build up of pressure, but it's not hard or painful to keep my finger on it.

@steve2006I'll have a look at the oil filler cap tomorrow and report back.

I have a compression tester - how do I do a test on this engine? Disconnect all the coil packs and remove spark plug from one cylinder at a time, then crank a couple of times? What reading should I be looking for?

Thanks everyone so far!

steve2006 · June 1, 2020

There should be 2 PCVs one one each side so it looks, from your pictures, that the driver’s side has been removed, if it is blowing out at that point it would indicate positive crankcase pressure.

A compression test is normally carried out with all the spark plugs removed then test each cylinder by cranking for a few seconds with the throttle held wide open. If a cylinder is found to have low compression a little engine oil is then squirted down the plug hole into the cylinder and the compression test repeated. If the result of this is an improved pressure this generally indicates worn piston rings, if there is little or no change it would indicate leaking valves are the cause.

Come back when you have done the test, expected values on a good engine are around the 170/180 PSI mark.

runsgrateasanut · June 1, 2020

A question as well as observation. If Power Steering fluid had been getting in, it would have looked more red in colour. It would have gone via the idle control valve presumably. Only oil colour on the Butterlfy valve.

Steve, you mention two PCV's is this the same for the LS400. I suppose it must be but I didn't notice when I last had my Throttle body off to clean. I recall replacing the passenger side.

Final Q. this morning I took out my Dipstick and the oil seemed to be three inches above the upper top level. Done this before and had the same result - until I asked my Mechanic to come round the following Morning and remove the dipstick. Exclamation!! the oil only at the upper most level and NOT on the wire, at all. Really scratching my head over this as feel that there may be excess oil as getting a bit of leakage from the Sump gasket.

Have you ever noticed oil on the Dipstick wire when you have pulled it from your Car, or has it always been between the level?

Antharro · June 2, 2020

Spent a couple of hours working on the car today. Removed all the air intake again, plus the coil packs and spark plugs. Was disappointed to see a small amount of oil on the bottom of the throttle body valve opening, which I cleaned.

Left bank plugs were mostly clean. Some oil on the threads but none near the tips or on the white part of the plugs. Plugs #1 and #4 (assuming #1 is closest to the firewall and #4 to the front of the car) were the oiliest.

Right bank plugs were much oilier, with two of them having dried on oil on the white part of the plug. All four had oily threads, and #1 and #2 had oil on the wider metal area immediately above the plug's thread. No oil on or near the tips.

Compression test results were:

Left
#1: 170
#2: 170
#3: 170
#4: 200

Right
#1: 168
#2: 185
#3: 190
#4: 190

I cleaned the plugs, cleaned the coil packs, cleaned the PCV valve pipework, re-assembled and started the engine... came up on about 5 or 6 cylinders. D'oh. Put a squirt of WD40 in each coil pack, reassembled. Found a wire had come out of the loom for R1 coil pack - shoved it back into its moulding - started the engine, came up on 8 cylinders, nice and smooth. No smoke out the back at all. Let the engine come up to temperature while I re-assembled the air intake assembly.

Noted that the left bank air valve (PCV thing) had a very small amount of oil on its outer surfaces and cleaned it off. Also noted that the cylinder head was oily around this area, as if oil had been leaking out of the air valve and running down the cylinder head. Not in any quantity but enough to be noticeable, and it had dried off since the car has been off the road. I don't believe that this valve is a valve; it's just a pipe that pressure vents through - a vent tube of sorts. It is a part of the cylinder head cover and is not adjustable and removable. If you take a look at part number 11201-50031 you can see that it's part of the cylinder head cover. You'll also see it on the pictures in this eBay auction: eBay Item 202864072539 and the pics in this thread on ClubLexus. The actual PCV valve on the right bank is a separate, removable part. Mint was replaced late last year. I didn't remove it but I did give its pipe work a clean - the inside of the pipe was slightly oily.

So where does this leave me? Given the oil in the air intake, it would still seem that oil is coming from the vent tube and PCV valve. I know it's a long shot, but is it possible there's sludge in the cylinder heads that's messing with the vent / PCV system and causing this? Bad gaskets somewhere? I'm pretty much out of ideas here!

runsgrateasanut · June 3, 2020

Out of my own curiosity I checked the answer to your Question written on the Photo. Its a Resonator. refer https://www.reference.com/world-view/air-intake-resonator-c953d81b49ffe3d1

Was the black carbon on your Butterfly disc dry or wet? My own was caked on and I would say quite dry,

Perhaps you are not getting exhaust gases into the throttle body which (and I'm only guessing) dries any liquid vapour that comes via the PCV valve.

An EGR issue perhaps? I have no real knowledge on the subject so someone with a greater understanding of these things will no doubt dismiss any connection.

Antharro · June 5, 2020

The carbon was dry but the oil was not! 🙂

Thanks for the info on the resonator.

@steve2006 Any advice you could give here would be gratefully received - thanks! Same for anyone else - I'm all out of ideas, beyond disconnecting the PCV valve and vent tube which I'm sure would only work until the next MOT...!

e2todd · June 21, 2020

On 5/31/2020 at 8:07 AM, Antharro said:

Where is all this oil coming from?

My theory is this - there's oil coming from the PCV valve, and from the pressure outlet pipe on the other side of the engine. There's probably also power steering fluid coming from the power steering pump. This builds up, gets sucked into the engine and burns off as nasty smelling blue/white smoke.

Hi having bought my ls430 just before lock-down, I've spent considerable time and money to rectify similar issues.

After cleaning the oil from my throttle body, I managed to replace both rocker cover gaskets, spark plug oil seals, PCV valve, rubber grommet and inlet connection pipe (all for under £50 off Amazon).

With fresh oil, plugs and filters all round (£150 from Lexus) this has all but removed my engine smoke on startup and full acceleration.

Hope this helps!

By the way, later I replaced the coolant temp sensor, installed refurbed injectors and remapped ECU too - what a difference!

The-Acre · June 22, 2020

8 hours ago, e2todd said:

Hi having bought my ls430 just before lock-down, I've spent considerable time and money to rectify similar issues.

After cleaning the oil from my throttle body, I managed to replace both rocker cover gaskets, spark plug oil seals, PCV valve, rubber grommet and inlet connection pipe (all for under £50 off Amazon).

With fresh oil, plugs and filters all round (£150 from Lexus) this has all but removed my engine smoke on startup and full acceleration.

Hope this helps!

By the way, later I replaced the coolant temp sensor, installed refurbed injectors and remapped ECU too - what a difference!

That sounds like a good result, what mileage are you at?

e2todd · June 22, 2020

9 hours ago, The-Acre said:

That sounds like a good result, what mileage are you at?

160K but previous owner was quite literally running it into the ground (collapsed air-suspension)

Similarly to David the OP, I've enjoyed doing my long repair list but there much left to do (belts, a/c, etc)

The-Acre · June 22, 2020

1 hour ago, e2todd said:

160K but previous owner was quite literally running it into the ground (collapsed air-suspension)

Similarly to David the OP, I've enjoyed doing my long repair list but there much left to do (belts, a/c, etc)

Well you're doing a grand job!

Antharro · July 23, 2020

An update!

I've now had the following replaced:

- Rocker cover gaskets x2
- Spark plug hole gaskets x8
- PCV valve
- PCV valve pipe
- Vent pipe
- Power steering vacuum valve
- Power steering vacuum valve pipes x2

Mechanic found a LOT of gunge in the rocker box - said it symptomatic of the car not being properly serviced in the past. The most gunge was around the top of N/S cylinder 1, incidentally the one that had the lowest compression.

I did a motorway test the day after I got the car back... it was fine until about 20 minutes in when it started smoking badly. I pulled off the motorway, switched off, waited a few minutes then started up again - no smoke. Drove for another 10 minutes and it started smoking again... this time I dropped it into neutral, switched off the engine, started it again, back in to D and the smoke was gone. No smoke at all for the remaining 25 minute drive.

And of course there was smoke at start-up the following day. But none during the town driving I did that way. There was smoke the following day but none while I was out and about.

I'm going to do another motorway test tomorrow and see what happens...

...but I'm thinking this either looks like a valve job or piston rings.