Is my car dying? Shaking engine bouncy idle

[eboy0]

Hello, first time poster long time searcher.
I've had this car for a little over 4 months now, been running up to my expectations(always had high idle). Until recently all of a sudden my idle went up from 1300 to 2000(once warmed up). Also, when i first start the car the idle is rediculosly bouncy, going from anywhere 1200 to 400 almost to a stall. Once the car is warmed up, it evens out anywhere from 1100 to 2000 but stops bouncing.
Had a compression test run on all 4 cylinders... almost 210 in each.
I put in new spark plugs: Bosch PLATINUM GAP=0.032"
The old ones were covered in so much carbon it was unbelievable.

I've calculated i'm getting about 9-10 mpg out of this car, so i'm guessing cat is clogged(getting that checked out monday) also may need new o2 sensor.

Does anyone have any idea whats going on with my car? Is the engine just dying? Is something else the culprit?

No check engine light has appeared yet, though the engine does shake ALOT.

If anyone has any info, that'd be great.

 

[inneedof]

Check for vacuum/boost leaks

 

[eboy0]

Check for vacuum/boost leaks

Thanks, i'll grab the supplies needed from one of the guides i found and get checking tommorow.
Any other ideas?

 

[andymoraitis]

210 compression is insanely high on a 4G63. I would suspect issues with the tester if you ran those numbers. I'd get a new tester and try it again.

Your low gas mileage and shaking idle lead me to point to one of three things:

1. Clogged cat (I see you're already replacing this)
2. Bad O2 sensor (these read lean and dump tons of fuel when failing)
3. Bad coolant temp sensor (runs rich because it thinks the motor is always cold).

Of the three, I'm leaning heavily towards one and two. Keep in mind that failing parts don't always trip a CEL and a combination of issues may be making things worse. For a new O2 sensor, try:

http://www.sparkplugs.com

These are Denso replacements that are plug and play. If you don't mind wire splicing, you can grab a Bosch sensor from a local auto parts store and try that.

Finally, get those platinum plugs out of there and replace them with NGK BPR6ES's or Autolite 63's gapped to .028. Our motors hate platinum plugs!

Let us know what you find out,

Andy

 

[eboy0]

Thanks for the reply, found out something weird today.. it was dark in the garage and i noticed the ignition wires are grounding themselves on the valve cover... electricity is going through the rubber.... good thing i noticed this! Got a new set of Accel spark plug wires coming sometime monday. Also took your advice Andy and bought those NGK sparks.
I'll grab a diffrent compression tool and give it another try...
I noticed it looked WAY off from what this site suggests: http://www.dsmgrrrl.com/FAQs/compression.htm
2.0L 4G63 Turbo engine
8.5:1
178 psi
133 psi
If the compressions come out the same again, where should i go from there?

Also, would the grounding of the ignition wires cause the sparks not to fire and cause the carbon buildup?

 

[andymoraitis]

Sure it can. Inconsistent spark will throw everything off. Give the plugs and wires a shot and see what it does. On the compression, I'd still re-test it and based on how much carbon buildup you've likely encountered, I'd consider a seafoam treatment (or two) to knock some of that crap out of there. Here's a reference thread:

http://www.dsmtuners.com/forums/showthread.php?t=222686&highlight=Seafoam

If that still doesn't do it, I'd look into the other options we discussed above. Hopefully, it's something really simple (and cheap).

 

[eboy0]

Ran the seafoam, got alot of smoke! Dont really notice a diffrence in performance.. but more problems arose... CEL went on for a while, then turned off. Found out i'm leaking compression from my 2nd cylinder from the left... the spark plug wire is literally POPPING out, it still has a grip on the spark plug, but it pops off...
Grrr.... looks like its a stripped thread... need to get that helicoil'd i guess. Also now the car, when i up the RPMs it like jumps, jerks like its trying to pull me but isn't like its supposed to... help??

 

[eboy0]

Ran a boost leak test, found a leak within seconds along the tubing where the BOV connects and runs to the intercooler.
Found sludge/oil in the intercooler tubing, which can't be good. Also at higher rpms the car shakes i mean like 5000+ it shakes but doesn't pull as much as it should..
Also wondering, would the carbon buildup and the high compression cause the engine to shake?

 

[unlinkedeclipse]

That happened to my 1G, if you already solved it, great. But on mine, we popped a vacuum line loose while removing all the AC crap.

 

[dieseltech]

A few suggestions from my experience. It is possible that you have so much carbon buildup that it's actually creating more compression and from what you describe of your plugs it's a good chance that's happened to you. I've never used seafoam to clean out carbon from cylinders but i have used a GM product called Top engine cleaner. It works great. Remove a vacuum hose and let half the can suck in, let it set for 20 min. Start it up and let it idle until it stops smoking. Finally suck the rest of the can in and kill the car by sucking in so much that it kills the car. Let it set again for 20 minutes. Start it and let it idle at 1500rpm until the smoke clears.

As for your sparkplug hole are you sure that it's stripped out? If so then you will have to helicoil it. I just changed the plugs in mine and they were all finger tight, . Torquing the plugs is a must!! Unless you have the patented torquometer elbow like i have You can buy a tool to chase the threads in reverse so you don't get any filings down in the cylinder. You will have to locate a tool dealer for this.

As for the sludge in your intercooler I'd suggest changing the pcv valve.

The shaking could be caused by the higher compression causing improper ignition. Try either Andy or my method of cleaning out the carbon. Then perform a compression test.
Retorque all your spark plugs. If you don't have a torque wrench once the spark plug becomes finger tight give it 2/3 of a turn. This is what it says on the NGK box I got my plugs in. Good luck. Keep us posted!

 

[eboy0]

http://img226.imageshack.us/img226/374/p1010082uj5.jpg

Theres one of my problems.... this gash was covered up w/ liquid electric tape.. other 3 had little cuts all up and down the wire.... got my new wires in today... CEL is GONE, car runs much better... spark plugs are starting to clear up, so i dont think i'm running rich anymore, but that's soon to be confirmed.... still got a bouncy idle, hopefully that'll clear up once i get my FMIC...
http://img166.imageshack.us/img166/7362/p1010075qg3.jpg

 

[dieseltech]

good nuff. good job troubleshooting!

 

[eboy0]

Still running rich... can't seem to figure out why.(I can smell if from exhaust, also still getting like 5-7mpg... ?) Anyone have any ideas?
Another seafoam treatment?

 

[slipstream808]

Do the seafoam in the cylinder and let it sit cleaning method. Make sure you have a shop vac!

 

[andymoraitis]

Still running rich... can't seem to figure out why.(I can smell if from exhaust, also still getting like 5-7mpg... ?) Anyone have any ideas?
Another seafoam treatment?

Low gas mileage is either a clogged cat or a bad O2 sensor.

Did you replace both of these as recommended?

 

[eboy0]

Cat is yet to be inspected, sometime this week.... o2 sensor is coming in sometime this week aswell.
If i poar the seafoam into the cylinders, i'd need a shop vac to suck it out? Hmm don't have a shop vac......

 

[eboy0]

Was bored today waiting for my parts.... decided to give some of these tests a shot.
http://www.geocities.com/motorcity/downs/7678/dsmtests.html
O2 sensor isn't giving me any reading... pins 1-2 are but pins 3-4 arent... does this mean its borked?

 

[dieseltech]

Those tests are for a 92 talon as explained so I'm not sure that the pins would be right. If the pins are the same pins 3 & 4 are the heating coil. The heating coil recieves voltage when you first turn the key on to aid the sensor in warming up. This allows it to go into closed loop faster, instead of depending of exhaust gases to warm the sensor up. When you probed pins 1 & 2 while running was the voltage toggleing fairly quickly or did it seem to output the same voltage for an extended period of time?

 

[eboy0]

When i probed 1 + 2, it was a quick reading then back to 0. If thats wut u ment.

 

[dieseltech]

First I'd make sure you are probing the right wires. Again the diagram is for a 92 not a 96 and I have no reference to look at right now to make sure they are the same.

 

[eboy0]

Ok, well after replacing the front O2 sensor, and driving around for about a day and a half, i'm not noticing an increase in MPG, and the exhaust is still making me tear up...(meaning i smell heavy gas) does the back O2 sensor after cat need replacing aswell? I'll post pix of the original front O2 sensor tommorow, it's pretty bad....
FMIC came in aswell! Soon to be one of my main projects.

Anyone have any idea bout the MPG?
Also, after my 2nd seafoam treatment, i dropped compression to 185 in each cylinder. Good?

You must be logged in to view this image or video.

 

[slipstream808]

You DROPPED compression?

That's good. Seriously that brings it down to "normal" levels which is very good. It means there is significant carbon buildup. Or at least there was and you got rid of it.

The second O2 sensor is to make sure the cat is working like it should, that's all. You'd get a CEL if it wasn't or if the 2nd O2 was messed up.

 

[eboy0]

So the 2nd sensor wouldn't affect my MPG? Something is still draining my gas fairly quickly... any other ideas?
Cat is not clogged btw. No gas leaks either.

 

[slipstream808]

No, the second sensor will not affect your MPG.

 

[slipstream808]

So, what are your problems at this point?
What have you fixed at this point?

This post has a lot to read, so I'd like to see where we're at by this point. Please be descriptive so we can figure things out.