jnovak01

Oil in the intake manifold is consistent with the Lexus RX PCV oil sludge issue.
Not that it is the only reason.
If it is Cylinder #4 it would be very easy to verify the reading. I recommend doing so.

Joe

salimshah

There is some (mis?)information running around the net circles. That is why I wanted to hear about what the dealership may have said.

Salim

oldusedone

After calling around and giving three different mechanics the diagnosis the dealer gave me they agreed with the dealer, my engine is toast and attempting to fix is cost ineffective. Oil usage and compression issue combined with manifold involvement tell them this. Further resistance would be futile, I'm lead to believe.

jimsRX300

What kind of tools do you have?

I'm still on board for a cost effective head swap IF the block is good and the cylinders are not scorched.

It's cost effective for its age. Just replace the defective head with a used one.

Can you at least ask? Say you will supply the head or heads. I'd help you, but I live in Ohio and have children.

Maybe cost a grand to 1500?

oldusedone

My tools and skills are far to few to consider this. When I discuss the situation with whomever I decide to go with I'll ask about this option. Thanks for responding with alternatives.

Paul

Nelexus88

Not having the tools and skills for auto repairs does limit your options. If it were mine I would pull the head since its easily accessible and see if the #4 exhaust leakage might be due to deposits holding the valve open. If so, it could be cleaned up and replaced for the cost of some gaskets. If that clears the misfire, sell or trade it quick, as it will not fix the oil use.

tllee

I think you should consider the following steps before you decide anything:

1. Autozone have loaner tool : engine compression gauge. Borrow one and test your #4 cylinder(it's very simple process)to make sure the compression is low. BTW, test #2 and #6(all located at front bank). No cost involed in this. If anyone of your #2, #4,#6 is bad , stop here and make your decision with no regret.

2. If the #2,#4,#6 are good(I don't trust dealers at all, especially in my area(NJ,NY metro),too much bad experiences), try to test #1,#3,#5, it's much difficult but can be done(check the thread "how to change your spark plugs w/o remove throttle body" link:https://www.clublexus.com/forums/rx-...-patience.html , it's same thing). If any of your #1,3,5 cylinder is bad, stop here and make your decision with no regret.

3. If you're lucky enough(I think that's very possible,since your car drove so good just not long ago)to find out your cylinders are all OK. Then, read this: I had same problem of oil consumption.How bad it is? I couldn't see any oil on my stick and oil pressure light still off(light bulb is good). When I took off my oil filter,it's completely dry. I was panic and check all 6 of cylinder's pressure, all were good. Then, I started my long internet search journey to solve the problem, final answer: change rear valve cover. It's Toyota's fault, they never want you to know that 1mz engine is very easy to suck up oil to intake manifold because of the design flaw of the rear valve cover. Toyota's sludge problem could very much related to this but I only have theory, there is no prove. If you go this far and want to know details, let me know,I'll give you a couple of links and you can read on.

4. If you go thru all above and come to here. The missing fire code(P0300, P0304) could be a bad iginition coil or spark plug. Change that, you're all set. You can drive your car again w/o any worry!

Hope this can help you go thru your difficult time, the cost for kid in college is high! I'm experiencing the same thing right now, that's reason why I keep my 02 RX300( I have it since Jan,02). Good luck!

salimshah

This is what I referred to (mis?)information on the net. Instead of hijacking this thread, I would suggest we start a new one.
For oil to enter the intake ... the oil level in the valve cover must get as high as the intake. The air filter side must be substantially chocked. Your timing belt would be soaked with oil before you get into intake.
Most likely cause is oil in one of the chamber which leaks past the intake valve ending in the intake.

Regarding valve cover/PCV, yes there can be an improvement but that does not mean a design flaw. A design flaw plagues all vehicles.

There is got be something that my mind is unable to comprehend.

Salim

salimshah

I have moved the discussion on oil in the intake to a new thread.

Lets leave this this thread unadulterated and on topic.


Salim

salimshah

Please do not post about oil in intake here. I have crated a new thread.

Salim

oldusedone

tilee,

While I think had I more suspicion prior to buying this car I could have avoided this whole mess I'm thinking the dealer is spot on with the loss of compression in #4. Sort of like going to see the doctor about a hemorrhoid problem, pretty much a open and shut case, you got them or you don't, no need to get a second opinion about that. Unless of course you are discussing treatment options. I'm ready to concede this failure. Since the car is 500 away I'd need to pay for that test again anyway.

I don't really understand the issue with oil in the manifold. Could it have something to do with my engine failure or is that not the case?

salimshah

I think we are all trying to suggest possible cures and help you make an informed decision.

What we are dealing with are
1. Loss of compression on #4 [unanswered q is are there any other cylinder with poor compression]
2. Consumption of oil.
3. Potential damage to engine caused by low oil

My personal concern (it seems like is common with the dealer and other mechanics) is that you dont take a path based on 'hope' and cheap(er) solution and then be disappointed in the end.

Lets go item by item

1. Loss of compression ... Can this be fixed by a head job. [tale the head off, new valves and re-seat. head gaskets, (valve-cover if it helps). If the problem is with the piston and rings then we are talking full overhaul. If you roll the dice and say lets do the head job then proceed to 2.

2. What would fix the consumption of oil? You dont want to be at square one after completing 1 above, unless you want to carry oil all the time.tlee thinks that a new valve cover will fix that problem and personally I am not convinced. This is where I wanted an answer from the dealer. If he concurs with tlee or any of the mechanics guarantee no oil consumption after the repairs then I would recommend that go ahead and get the repairs done.

3. Potential damage to the engine .. This worries me the most. Although I suggested ways to check the pan and filter. That would have been fine by itself provided you did not have 1 and 2 above. Maybe with just 2 you could carry oil and live with it. On this issue you will find me, and the dealer and other mechanics unwilling to take the risk of partial (good faith) attempt to fix and then find out the main bearings have been compromised. Only sure way to fix is engine overhaul.

As I am composing this note, I am almost sure you have thought of all these. Hopefully reading a 3rd person's note, will help you make the decision after considering your personal situation.

Salim

fastnoypi

regarding the suggestions by others for head replacement as a solution to the #4 cylinder low compression, ..a leak down test should be able to determine if the head is the problem vs the damaged rings. This would save in unnecessary tear down costs.

For those who are unfamiliar with a leakdown test, compressed air would be pumped through the spark plug hole while the engine would be rotated till the questionable cylinder is at TDC with all its valves closed. The process is to be repeated on all cylinders to find the mean.
On average normal leakdown should be around 10%. A head with a bad valve..chipped or bent, will show a high reading. A bad exhaust valve would shoot the compressed air out the exhaust. A bad intake valve would shoot a rush of air through the intake manifold and can be felt at the throttle body when the butterfly is opened.

AnthonyMtz

All this trouble dosnt seem worth it to rip your hair out over lol I would just get the engine replace with a nice used one, Paul I did send you the links to those engines. Not sure if you got them anyways for some reason every time I drive my Rx and open the hood it smells like somthing Is burning, then I look towards the front exhaust manifolds right where they meet up with the engine and it looks like it's wet with oil....worder if my valve cover gasket is leaking?

tllee

Well, it totally is your decision to make. Change of rebuild an engine will cost a lot .
The rear valve cover issue need to be addressed if you're going to keep this car. Before the the engine installation, changing an rear valve cover is a piece of cake. So I strongly recommend you to do that.
Please see the new thread been created , you will find details causes of the oil in manifold , it's very possible related to your engine issue. Also please see this link below:
https://www.clublexus.com/forums/rx-...0-miles-5.html Post #66 may answer your question