GoGiantsNJ

Time to go to another Lexus Service Department,or a reliable Indy mechanic for a second opinion for the fix.

nayilsi

Got my car back from the dealership today. The shop foreman was telling me that he found cylinder 3 was at 60 psi and the rest of the cylinders were at 120 psi.

I thought our cars would put higher psi than 120!

Anyways, took to it an independent shop (Bmw and merc specialists) and they're saying that there's no way our cars would have low compression unless it wasn't maintained at all. The shop is certain that it is the coil or the spark plugs and they are going to replace those.

Gville350

iTrader: (10)

I'm not sure what the proper 2IS compression psi should be, but comparing a Nissan V6 at 185 nominal compression and 142 lowest acceptable compression it doesn't sound right.

nayilsi

Mechanic changed the plugs and the coils and the CEL still comes back on.

My IS is really sick.

Gville350

iTrader: (10)

Tell them you need a compression test and leak down test performed.

keyframe13

Subscribing to this. I had the exact same problem with my acura tl. Check engine light on, TCS came on few seconds after I started the engine, O2 sensor was the code. Changed few of them , problem persisted. Low RPM when AC was on. other than that car was running strong.
p.s. My car ran with this issue for over a year(13k miles) didn;t got any worse. I recently sold it so I'm really curious what was the cause of that.

Ramon

Just curious, if there is in-fact a cylinder with low compression, does that automatically mean a new engine? Couldn't something as simple as a blown head gasket also cause compression loss? Not saying a blown gasket is a simple or cheap fix, but certainly beats buying a new engine.

nayilsi

The mechanic called me back today. He said he test drove the car for 40-50 miles and no lights came on.

I asked him if he did something special before he drove the car. He mentioned that he did try to play around with the coil/plug wires and ever since that he hasn't seen the CEL come on.

He also mentioned that the car is idling fine.

I pick up my car tomorrow. *Tensed*

nayilsi

does that automatically mean a new engine?
Nope.

Couldn't something as simple as a blown head gasket also cause compression loss?
Yup, even valves. I think rings and pistons are the major problems.

Lexus Tech recommended complete engine tear down and possibly the block needed to be replaced. Whereas the service lady told me that I needed a new motor.

I hope my indy mechanic isn't BSing me about the CEL being gone.

Gville350

iTrader: (10)

Low-compression symptoms can be caused by :

1) bad head gasket
2) excessive P2W (piston-to-wall) clearances in the bore
3) bad piston rings
4) burnt/bad valve
5) bad compression test or tester reading

*You can perform a dry or wet test; a wet test should increase the compression. A compression test should be performed with a GOOD battery & starter that can crank the motor easily for all cylinders. Cylinders shouldn't have > a 5% margin from any other cylinder.

Obviously here there were a lot of people saying this and that without KNOWING FOR SURE that the motor was bad (low compression). Before spending loads of money of accessory-type items, get a leak-down test with compression test results.

OP, hope you just had a faulty connection somewhere and the CEL will stay away. BTW, dielectric grease is VERY useful to help cut down on these types of phantom wiring connection issues.

GL!

nayilsi

Ok here's what I did.

Took the car from the indy mechanic. No CEL showed up.

Went to a Mazda dealership and traded it in for a 2013 speed3.

Thanks for the help GVille and rest of the CL crew.

NimaM

iTrader: (1)

Nice!!!