Have I got a problem for you!

[ADrewzki]

So the other day I'm taking my car out for a spin. I floor it and it hits 100 pretty easy on wide open road. I slow and I realize that my engine is not firing correctly and I have boost creep. Not a little bit of it either. It idles at 3psi vacuum. For some reason, my #1 cylinder is not functioning either. The vacuum leak is from the SMIC I think because I backed out of my friend's driveway kinda funny and it felt like his huge curb might've made contact with it. Hopefully leak test will get done soon and I'll verify this (or not). I took the car in and they mechanic told me that he has no idea why cylinder #1 is not firing without "testing" (tearing apart the engine). For $1500, I can do that myself. So here's the question: Is there any way that a malfunctioning cylinder can cause boost creep? Camshaft turns, idle jumps around from 600-800, nothing is seized, and I still drive it around slowly. If anyone can give me any ideas, regardless of how remote and far fetched, I'd appreciate it.

 

[BUCK]

Doesn't answer your questions but I take it "mechanic" threw a new plug and/or wire on #1 just for giggles? When #1 plug is out & you spin motor over it's making some kinda Compression?

 

[Enigma_Man]

Boost creep doesn't make your vacuum higher.

You possibly have a huge intake leak.

-Jesse

 

[ADrewzki]

So I went to another Mitsu dealer today. They actually pulled out my plugs. Spark plug in cylinder #1 was well....there wasn't much left of it. It looked like it had detonated. They pulled out the other plugs as well. #2, #4 were still ok. #3 looked like it was ready to go the same way. Compression was a little low in #2 (100) and the other two were ok. They're assuming a bent valve because they're telling me that the piston head crushed my spark plug. If that was the case, would I not have heard a tapping or something? Just seems odd that I drove the car from COLORADO to SOUTH CAROLINA and it worked fine. Oh, btw, do NOT buy champion plugs (I had to because no auto store in CO would sell me NGK). Anyone know of any hookups in SC?

 

[Dallas J]

The mechanics are feeding you nonsence. Your piston wont hit your plug unless you break a rod or something. You dont have a bent valve if you have more than 100psi of compression. Bottom line is that you probably boost creeped up too high, detonated and burned the spark plug.
Get yourself a new set of NGK BPR6ES's and find your boost creep issue.

Do a pressure test to check your IC, and everything else to find out why your getting such low vacuume.

-Dallas J

 

[ADrewzki]

Originally posted by Dallas J
The mechanics are feeding you nonsence. Your piston wont hit your plug unless you break a rod or something. You dont have a bent valve if you have more than 100psi of compression. Bottom line is that you probably boost creeped up too high, detonated and burned the spark plug.
Get yourself a new set of NGK BPR6ES's and find your boost creep issue.

-Dallas J

That's kinda what I'm thinking too but there's no compression in cylinder #1. #2 is right at 100 so I'm thinking that one is ok for a while. The only other thing that I can think of is that maybe I have a seal that's not good anymore maybe. That's what could cause no compression, right? And yes, I'm going to start running colder NGK plugs from now on.

 

[Defiant]

Originally posted by ADrewzki
It idles at 3psi vacuum. For some reason, my #1 cylinder is not functioning either. The vacuum leak is from the SMIC I think because I backed out of my friend's driveway kinda funny and it felt like his huge curb might've made contact with it.

Sorry, but nope. Vacuum is only between the throttle plate and the piston-tops. All the intake between the turbo outlet and the throttle plate is only for boost- it will only see vacuum at part-throttle. I don't know what you've done to your motor, but 100psi compression is too high to be a bent valve, and as said above, the pistons don't touch the plugs. Ever. However, it's also too low a compression to have a running engine. Whatever you did, or whatever happened, your motor is done.

 

[92awddsm]

How in the hell can a dished piston ever hit a spark plug that is recessed in a combustion chamber? Only if it melted and began to come apart. Hence crushed plug, no compression, no vacuum, and the shop telling you they have to pull the engine apart to find the problem. Could be a burnt valve, could be a burnt piston. They dont know and dont care at this point until you commit to spending more money for more of their labor time. Pay attention to the boost gauge or wire up a boost warning light from a pressure switch.

 

[builtTSi]

I think he said that he has zero compression in number one and 100 in number two. I had a similar problem with my engine. number one had a 98% leak, (leak test performed at the dealership) It was like running on three cylinders. It turned out my timing belt jumped time just enough to bend the exhaust valves on number one cylinder. And no I hadn't heard anything hit, no noise what so ever. The mechanic said that it doesn't take that big of a hit to bend the valves just enough to unseat them. I pulled my head, pulled the valves and sure enough the seats had build up on them where it was leaking at. So I bought 2 new valves at Napa for 12 bucks, machined, and installed them. Problem solved. As for the compression in number two, it may be time for some new rings...just a thought
As for the messed up plug. I have no idea, but like everyone else said there is no way your piston hit it.

 

[92awddsm]

If you had 98% leak, you had compression. You have to have compression before you get leak. 0 compression= 100% leak. Boost creep leads me to believe something more serious than a bent valve but one way or the other, the head really needs to come off. Hell, who nows, could just be a head gasket. Dont know till you do it.

 

[builtTSi]

Originally posted by 92awddsm
If you had 98% leak, you had compression. You have to have compression before you get leak.

Yeah I had very little compression. The valve sealed just enough to hold 2% compression. Point being, if his valves are bent bad enough he could have zero compression.

 

[MNGSX]

If you don't have alot of racket at idle it is'nt a broken rod.

My guess is you melted a piston and the plug was exposed (inhabits the same environment) to the same heat from severely leaning out at high boost... probably from boost creep and cold air. Plug melted/exploded in excessive heat and or detonation that comes with it and the piston has a hole in it.

 

[BUCK]

ADrewzki - call me - #'s all over my website - I'd like to help if possible.