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2009 Corolla tech in Chit-Chat....low compression

dntsdad

Central California
Joined
May 19, 2020
Member Number
47
Messages
1,267
Loc
Central California
2009 Corolla, 4 cyl, 140k miles

Starts and idles fine. Put it in reverse or gear and idle struggles down. Doesn't die. Can drive it without issues, until you stop at a light and then it feels like it may die, but it doesn't.

no smoke, water, or condensation from the tailpipe.

New plugs and swapped the coil packs around without change in performance.

Went and rented a compression gauge kit from napa.

1=150
2=125
3=75
4=90

Head Gasket fuckered??
 
Has it been overheated? Dump a tablespoon of Oil down each hole right before the test and see if the numbers come up.
 
Sons car and I know that he lost the radiator top plastic tank about 1.5 years ago. not sure if it overheated then or not honestly.

But its been running fine for the last 1.5 years until last week. Then the low idle thing came out of the blue along with the misfire code which caused me to start swapping coil packs to see if one was bad.
 
Well shit, I just went and returned to pressure gauge.

I can go rent it again and try that.

What does that do? Just so that I can learn something here and what would it tell me?
 
Well shit, I just went and returned to pressure gauge.

I can go rent it again and try that.

What does that do? Just so that I can learn something here and what would it tell me?

it lets you know if you have a ring issue or not.

Compression goes up with oil added then the rings are bad.

If it does not you have valve or gasket issues.
 
I have one but the old as hell one I have doesn't have the long hose or extensions to get down the long tubes on the OHC cars. Never needed one for that.
 
I have one but the old as hell one I have doesn't have the long hose or extensions to get down the long tubes on the OHC cars. Never needed one for that.

Next step is something to hook compressed air to the screw-in part of the compression tester. The see if air is coming out the intake, exhaust pipe, cylinder next door or radiator when you put air pressure into the lowest cylinder.
 
Did you check compression more than once? Low compression correspond with the misfire code(s)?

it didn’t just get a new battery did it?
 
Did you check compression more than once? Low compression correspond with the misfire code(s)?

it didn’t just get a new battery did it?

I went 4,3,2,1,2,3,4 to recheck the the really low ones again.

I couldnt remember what code i got as far as what cylinder.
 
low compression sucks but the idling down doesnt really correlate with those issues. Unless it was feeling like it was misfiring or low on power all the time.

Have you looked for a vacuum leak?
How about idle air control valve?

Clean the throttle body

pcv functionality?


My gf has a 07 corolla. And the pcv shit out on it doing this once.

1.8L?
Specs for compression is 199psi
Mininum is 157 psi
With difference per cylinder max of 14 psi
 
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If coolant gets in the combustion chamber it will set off a miss fire code. Pull the plugs and see if they are wet. If they are wet replace the head gasket.
 
When I pulled them for the compression gauge, they didn't really seem to be wet. I didn't notice it at least. I also had all the plugs out when I did the compression on each cylinder but I am not sure if it would mist out coolant or get the gauge end wet in just a 10 second crank for the gauge.

Codes were 300, 303, 304
All misfire codes. 300=random cylinder, 303,304 and 3 & 4 cylinders. My low ones

The only thing that I have done is pull the electiccal connectors one at a time on the coil packs to see if I got an idle change on all of them, which I did. Googled those symptoms a bit and ogt a lot of head gasket failure so I check the compression today.

Thats it so far.

Yeah, its the 1.8
 
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low compression sucks but the idling down doesnt really correlate with those issues. Unless it was feeling like it was misfiring or low on power all the time.
i

I agree, it doesn’t really make sense, I would expect some other symptoms to go with low compression.

Most late Toyota idle issues are from a dirty throttle body
 
That is a vvti engine, I wonder if the cam sensor is causing the cam phasers to tweak out?
 
Tight valves. Specifically tight exhaust valves most likely. Pull the cam cover and check.
 
Did not get much time today to mess with this thing. I ended up pressure washing it as step 1 cause it was dirty as hell, and of course the pressure washer wouldn't start so I spent forever working on that.

Anyways, got it clean and sprayed it all down with a couple cans of carb cleaner looking for vacuum leaks. NADA. Never surged in idle. I don't have a smoke tester.

Hooked up the scanner/phone app and it only had codes for the coil packs. All 4. This was when i pulled the connectors one at a time last weekend. Since then it had been driven about 150 miles without any other codes.

I cleared those out and drove it around for about an hour. Stop and go, long country roads, etc. It drops idle at a stop, and feels like it is sluggish off the go, but I also haven't driven this car in years so not sure if that sluggist is just the 1.8 compared to my v6 accord. Runs fine at speed, even when I mash on the throttle to kickit down into a passing situation. Some pinging that I hear for sure but nothing that sounds like it going to fall apart.

I would never thing low compression, especially at those levels, if I would not have tested it. I would think vacuum leak but I cannot find one anywhere. The PCV is something that I will give a shot I guess for $10 but its a bitch to get to apparently from YouTube videos and didn't have time to get to it.

Also. my phone app has a dealio to run "extended tests" so I hit that and got back a code 5241. No letters. I have no idea what that is. Only codes I have ever dealt with are P0XXX. Anyone have an idea on that?
 
Apparently low compression, very similar to your readings, is common for '09 shit boxes. Everyone complained of rough idle as well.

I never saw a fix as I think people just unloaded them to the next sucker.
 
I really do not want to rip the head off this thing. This is my son's only car and he has no money to replace it and has about zero mechanical inclination.

I got gas today to drive it around cause did I mention it was my son's car so of course the damn thing was empty. Anyways, left it running just because while I got gas and there was a loud puff puff puff out of the gas cap when I removed it. I honestly have never gotten gas with the car running that I can think of so not sure if that is normal. I know that the tank will pressuring normally so maybe that was what I was hearing with the EVAP working.

Also, the sound out of the exhaust is definetly louder and deeper than normal. Not like a Harley or a V8 or anything but different.

I drove it around about 20 miles and no codes although it it very sluggish from a stop and idles in D or R like shit. If it is in P you can wind the shit out of without an issue at all, and driving at speed, it feels perfect.

It really feels like a vacuum leak so I guess I may build that smoker in the link above and see through the power brake booster line.

Fuck, I might even try to Seafoam it. Longshot as hell but I am willing to smoke up the neighborhood and see if there is crap not allowing a valve to seal or something weird.

Does the block never, rarely, often have to be machined after a HG fail? I know that the head should be looked at. If the block has to come out, this thing is getting donated to Woman's Shelter charity or something.
 
They are common to pull threads in the block. It’s not a deal breaker, but if you are going to pull the head for some reason you need to plan on having inserts put in the block. Ron at Hiatt machine does it.

I Would not consider pulling the head until you know why it has low compression.
 
No idea what NAWS is

I bought a leakdown gauge today but I have never done that before.

From what I can tell from reading up, I should get about 10% leakdown (because of #4 below) under the best circumstances. If it leaking more than that, I am going to get that air leaking to the failure point.

Could be
1. The exhaust pipe - exhaust valve not seating for whatever reason
2. The intake - Intake valve not closing for whatever reason - Can I pull the boot of the throttle body and hear the air through there.
3. Coolant jacket - Pull radiator cap off - should see bubbles
4. Back through the rings - I should get SOME leakage back because without oil and static, they will leak a little??????? If it leaks a LOT, then I have issues with the rings.

Do I have this about right?

OK, I am not looking to pull that head off, but diagnosing exactly why its leaking and where it is, is something that I am not sure as I don't have experieince diagnosing this type of thing. Just never had to.

And yeah, if I have to get work done itll go to Hyatt
 
Check and see how much Vaccum its pulling, I worked on one a few years ago where the Catalytic converter had broken into pieces and plugged up the exhaust. It was pulling a shitload of vaccum at idle and higher in the rpms. Replaced the Cat and it ran perfectly fine.
 
Check and see how much Vaccum its pulling, I worked on one a few years ago where the Catalytic converter had broken into pieces and plugged up the exhaust. It was pulling a shitload of vaccum at idle and higher in the rpms. Replaced the Cat and it ran perfectly fine.

This is a good idea.
 
How many fucktarded opinions can be posted in this thread?:lmao:
Cylinders 3&4 are very low on compression. Replace the damn head gasket. It only takes a few hours.
 
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