xion0374

There has been an issue with my Rx 300, I had the vechicle for little over 3 years now. Its been a reliable car for me, no issue whatso ever. However last fall, my engine started acting weird.


The check engine light came on at the same time the TCS/PSC/PSV, which caused my engine to idle roughly, and at low rpm it feel hard on the engine. I have done regular oil change on the car once every 3k to 4k miles.


But before this, everytime during cold startup, my engine will burn a small amount of engine oil, causing a blue vapor out the tail pipe, but only on cold startup. Once the car has warm up, theres no more engine oil being burn. However, I slowly losing engine oil over a 3month period, to where I almost have no engine oil.


Now fast forward to when my engine was idling rough, I put the car to rest for over 7months during the long cold winter. Have not touch the engine since then, until today.


Went to go and try to start the engine, there was nothing coming from the engine. Which is weird, because I just put a brand new battery before I put her to rest. Turns out the battery was drain, which isn't an issue, charge her up fully and plug her back in. Crank the engine, there was a moment of engine crank, then the click click click click from the starter follow immediately afterwards.


Took the battery out, unplug the starter and brought it over to autozone, had it checked. The battery was in excellent condition, the starter was still good. Came home, plug it back in, try and crank it again. The engine just started to crank over and then click click click click from the starter.


Now I don't know whats wrong with the car, if battery and starter is still good, what am I over looking. Please help, I don't want to spend 3k to 5k on brand new motor. The engine has 200k on it, original miles.


Please help.


Thanks.

xion0374

-Update-


Ok, so I swap out battery from my other vehicle over onto the lexus rx 300 that wouldn't turn over, it appears that the battery was just drain.


The car turn over with the swap, now I can go to step 2 of my diagnosis.


Since the check engine comes on and is flashing, does this indicate that I am having a misfire from one of my cylinder, and if so how do I go about diagnosising it to find out which one is bad.
Step 3 is that I want to redo the head gasket and probrably the water pump and timing belt as well, since this car is 200+ miles on it.

salimshah

To get the terminology out of the way ...

Is you RX holding idle or it just sputtering (tries to run but can not maintain idle)?

I would not go about replacing anything until I find out what is going on. If you go about following hunches, you may fix the problem but most likely you will not.

Get the codes read and then we suggest best coarse of action.

Other things to check would be compression test, leak down test.

Salim

xion0374

Just got the car up and running. It is idling fine atm, but when I drive it later, Im pretty sure that the check engine light will come on, follow by the VCS light and then the check engine light will probably start flashing.


Now I have to wait and get the code to regenerate again and see what I pull from the codes. Will update.

salimshah

Codes go from 'pending' to 'error' after pending has been around for a while and if sensors generate good values, the pending gets flushed out.

If you have access to a reader, you can observe the pending codes, but dont jump to make repairs till the 'error' codes are set. I just jot the codes when they appear and then I clear them. Only when they come back the second time, I start investigating.

If you had bad/weak battery, I would ignore the codes and attribute the failure due to bad environment.[sensors do not produce right output when the battery is bad]

Salim

xion0374

So, I decided to open up the engine. I was able to take the air intake, throttle body, intake manifold and the front cylinder valve cover off.

To my surprise the engine isnt doing to badly, theres not gunk or oil residue which is good.

But I need to get the cylinder head off the block, but its a pain in the *** since I dont have the nessary tools to do the job. It was already difficult enough to get one cyclinder head cover off but to get to the cylinder block is going to be tough.

Now, Im stuck at the camshafts and timing belt. The timing belt may not be hard to get off, but the camshafts will be difficult, as I will have a hard time getting it to time correctly back onto the cylinder head.

How should I go about doing this part.

salimshah

There are different DIYs posted here .. look at the sticky. There is one on timing belt [will cover the front]. There is one on knock sensor [will cover the top].

But what drove you to do this.? I thought you had the rx running.

Salim

fastnoypi

how did you determine you need to remove a cylinder head? did you do compression and leakdown tests to confirm a head issue or determine a head gasket failure?

xion0374

I determine that I need to take the cylinder head off because I wanted to check and see if the oil was leaking in through the valve seal inside the cylinder head because the engine was burning oil every time on cold startups.


Plus, I know for sure I need new valve seal for the valve cover, plus need to change out spark plugs behind the intake manifold. So once I did this, I notice oil leakage from the valve cover, but I cant tell if oil is leaking through the valve inside the cylinder head. Im not sure if compression can determine if the valve seal inside the piston chamber are loose or bad, since I don't have a compression tools.

fastnoypi

i think your diagnosis led you to a false positive. 1st gen RX's are known to smoke oil for short trip cars that do not have time to heat and burn condensation from blowby.
The cause is typically the rear valve cover's internal baffle being clogged from sludge. The fix is to use the latest revision of the rear valve cover. Or you can recondition your existing valve cover by chemically cleaning, unfortunately it takes a considerable amount of time effort.

Note, your starting issues and oil consumption issues are two different problems and not related.

xion0374

yea so at this point I wont be taking the cylinder head off, instead I'll just replace the rear valve cover seal and the front valve cover seal as well, hoping that there wont be any more oil leakage into the intake manifold or through the cylinder seal.


The starting is probably due to some misfire im getting either from the coil packs or spark plug or I believe there was one other thing that also causes misfire too, I believe it was a sensor of some type.