dirkdiggle

iTrader: (1)

Hi,

Was driving along on the highway yesterday just fine and all of a sudden I noticed the Rx300 running weird with lack of power. Shortly after the Check engine light started Flashing. I had to drive it another 35 miles like this with the light flashing and running rough.

I looked into the issue thinking it was a coil and its not the coils because I am getting spark on all of them.

I checked compression on cylinder 2 and 4 and 6. with a cheapo $50 gauge

Cylinder 2 has 60psi
cylinder 4 has 170psi
cylinder 6 has 170 psi

obviously the issue is with cylinder 2 having 60psi compression.

What are the possible causes for loss of compression in the cylinder?? Anything I can try and put down in the cylinder hole to try and correct the issue? Im hoping the actual piston and rings are not toast.

The check engine light does not always stay flashing......once in a while I noticed the light would stay solid and the car seemed to drive smooth and normal for a little while and then would go back to flashing and riding rough. It did this a couple of times on the ride home.

Car info:
175k mile
Has a rear main seal leak and I keep eye on oil level
Burns oil on start-up once in a while but not always.
I did try some of that Barrs rear main seal leak fix about 2000 miles ago.

Any ideas or insight are welcome?

dirkdiggle

iTrader: (1)

Figure at the very least have cylinder 2 rebuilt. What would it cost to have just the cylinder 2 rebuilt?

Z07

pour 1 table spoon of engine oil into #2's spark plug hole and retest.

If compression remains low the leak is in the head.

If compression rises the leak is piston rings.

kalali

A low compression does not increase on its own unless there is an error in measuring. If the engine runs smooth and normal every now and then as you describe, then there is something else going on. If the 60psi is confirmed, you'll need to look for a replacement engine. You may also have issues with 1,3, and 5.
How many miles on the engine?

dirkdiggle

iTrader: (1)

It runs smoother and engine light stays solid once in a while and only for short amount of time while driving along but when I come to a stop light and idle it starts running rough again and light begins to flash/blink. Seems like certain Rpm's it smooths out but whenever it is at steady 2k rpm its roughest for sure.

has 175k miles
Cylinder 2 has 60psi
cylinder 4 has 170psi
cylinder 6 has 170psi

Something is obviously wrong with cylinder 2 ...... That low of compression cant be normal.

salimshah

Is the problem above or below ... Cheapest fix would be a valve problem.

Salim

dirkdiggle

iTrader: (1)

I poured a little 10w-40 oil in cylinder 2 and checked the compression again. No change in compression. So most likely I have a Valve that isnt sealing properly or chipped correct?

What would it typically cost to change out the valves and seals on cylinder 2?

seems pretty easy to access.

salimshah

Who ever quotes you price ask about all optional stuff like, timing belt, water-pump, cam-seals etc.

Without that you will get numbers that are all over the place.

Salim

Z07

Look under the oil fill cap. Does it look like either chocolate milk or really thick Bailey's Irish Cream? If so, head gasket is shot.

If not, I'd beg borrow steal or buy a bore scope and watch the valves close on #2. If they move linearly suspect spring. If they move laterally at all then valve seats and guides are shot.

Springs are cheap. An IRAN (inspect replace/repair as needed) of the heads is going to cost $200 and up to ??? depending upon what they find and that is with you taking the head to the machine shop.

Were it mine, and if I saw the valves moving sideways I'd seriously start looking for an engine out of a low mileage wreck for about $500 and swap parts or drop in whole depending on condition.

dirkdiggle

iTrader: (1)

Is removing the complete front cylinder head pretty easy? Is it easy to get back together and have the timing right?? Im sure if I remove it and bring it into the auto shop myself I will save lots of money.

Z07

Read the DIY sticky for timing belt replacement, watch some youtube videos for head gasket replacement, and see if local help is available. By that last part I mean look in craig's list for your area and find some mobile mechanics and get quotes for doing the R&R. File that away as your safety net if you get stuck. Digital camera, FSM, and excellent torque wrench are must have items too. The timing isn't a problem as the cams' gears, the belt, and the crank are marked with assembly-line proof markings to help.

Before you go down this road make certain of your diagnosis.

dirkdiggle

iTrader: (1)

I drove it today to drop off at shop and it seemed to run good on the highway. 70 + mph the check engine light went away and seemed to run normally. Seems just at low speeds/rpm it runs rough and engine light flashes.

Assuming its just a burnt or pitted Valve thats not sealing properly.....how bad is it to drive the car like this??

Im not sure its worth putting thousands of dollars into fixing such a high mileage car and if its safe or not that bad to drive it with just a bad valve I might just deal with the rough idle and rough at low rpms.

I mean could I potentially drive it like this for a long time or is there a high probability of it destroying the entire engine?

Thanks for help thus far.

kalali

There are a lot of folks here with more than 175K miles on their RXs and have no running issues. You need to find out what caused the damage to your engine. Normally an overheat, low engine oil, overreving, etc., could cause catastrophic failures. As far as the level of difficulty is concerned, you need to judge that based on your own previous experience. At the minimum a job like this requires tools and a factory shop manual and plenty of time doing it the first time. And if you decide to do the repair, you should consider doing the valve job on both heads. I don't think I've heard anyone go through all this trouble anf just do one cylinder.
Keep us posted.

dirkdiggle

iTrader: (1)

Mechanic at toyota dealership just told me I have a Burnt Exhaust valve on cylinder #2.

He says I can drive it like that but will have bad gas mileage and could mess up my cat converter.

Any other damage likely if I just drive it?

I can deal with the rough idle and and the MPG estimator on the dash doesnt appear to be that much lower than normal when driving it.

Just not sure its worth dumping thousand Plus on fixing that valve.

hypervish

How much longer do you see yourself driving the RX?

For me, it's a no brainer! I'd get it fixed. Cheaper than buying a new car, and making payments.