I was @ my dad's house Sunday, to replace my coil springs as they are shot. I soon found out that my passenger side spring perch is completely rusted out & barely there.

If that weren't bad enough, my dad said it sounded like I had a dead cylinder. I pulled the plugs & they all looked fine, however, when we did a compression check, 2-6 had 140-150#'s of compression & cylinder # 1 had 80#'s.

SON OF A B****......

My motor has 119,000 miles & is a 4.0. When I bought it, it had sat for nearly 4 years with less than 1000, maybe less than 500 miles on it a year.

I have yet to remove the valve cover to check anything out. I'm inexperienced to say the least.

Fast forward to tonight, I was on my way home. I'd probably driven 15 miles when my Check engine light came on. My Maintenance Required light has been on for awhile do to something else. I turned off the road & came to a stop, the engine stalled out & the "oil" dummy light was lit up. I popped the hood to take a look.

It seemed like the valve cover over the low #1 cylinder was surprisingly cool. I started it back up & drove another 3 miles home. The light did not come back on & when I got home & popped the hood, the valve cover over the #1 cylinder was now warm.

Any ideas what it could be or what I should check?

Sorry for the windy post, any help is appreciated..

 

Start by pulling the error codes.

The low compression on #1 means that there is no combustion taking place. The heat you felt was from the other cylinders firing and the hot coolant circulating thru the block and head.

I'd start pulling the head and inspecting the gasket, intake and exhaust valves/seats

 

Or the compression is being leaked somewhere, hows the rings?

 

x2 did you do just a dry compression test or a wet test too? also how about a leak down test???

 

Before you pull anything apart do a leak down test!! Obviously something is wrong and a leak down will tell you where. Chances are you wont see anything just looking at it when its apart and then you wont know where to go.

 

x2. Leak down rules.

 

As I stated earlier, I am nw to all of this & a complete amateur.

What is a leak down test?

 

A leak down test measures how much air is escaping the cylinder and you can determine if its psat the intake or exhaust valves, the rings, or if something is broke or cracked.

 

Ok, I searched yahoo & found out what a leak down test is. Now I just need to see if I can get a compression tester to check it. Maybe my dad has one.

Thanks for the help fellas.

 

I just bought some Seafoam. I let it suck some of it into the break booster line, the rest into the oil fill & finally a little into the gas tank. I may be crazy, but, I would swear that it "sounds" like the compression is up on the 1st cylinder. I don't even know if it can work that quickly, but, it definitely sounds better upon crank up.

I'll check compression tomorrow then try to leak down test.

 

Harbor freight has a leak down tester pretty cheap

Make sure you change the oil after adding the seafoam to it. Cleaning out your engine shouldnt fix a leaky cylinder. Maybe you cleaned out the others so they are all running smoother? I seafoamed my jeep the other day and its been running smoother since then.