Compression test...

First off, Ill start with my fuel mileage. I replaced the primary and secondary fuel filter last weekend, and Ive put 220 miles on the car with 11.1 gallon fill up, and the needle is getting pretty close to Empty. Obviously there is something wrong with my mpg. This tank also has had a bottle of Seafoam put into it as well.

So, I took my car into my Auto Tech 3 class at my high school, and a friend and I took out my plugs, and checked them, cleaned them, and checked the gap, and put the plugs back in. One of the plugs(on the number 2 cylinder) smelt a little like old gasoline....

So, later that day, I put my car up on the lift to try and weld an exhaust leak, but we needed to take the pipe off to get to the leak a little better, and we were running low on time. I walk over, and notice some oil on my oil pan, and call my teacher over. We look around, and find that the whole pan is slick with a thin film of oil. My teacher said that it maybe a faulty head gasket. We do a compression test, and I got 150, 140, 140, 130(Cylinders 4,3,2,1, respectively...with 4 being on the far left, 1 being on the far right, facing the engine bay). These numbers seem pretty low to me...exactly what should the compression be running at?


Also, Ive noticed a slight waver in my RPM's at idle. They will jump a little low, then a little high. My teacher says it may be a miss in the engine. We pulled plug wires one at a time while the engine was on, and the engine sounded like it was going to crap out with each wire pull(which is good, showing that the wires are all firing properly). My dad is really good and proficient with Honda cars, and he said that I could swap out the Number 1 and 4 plug wires around on the distributor and try to crank the engine over, so that it would blow any crap thats in the carb and in the intake out. Mind you I did this AFTER I checked and cleaned my plugs, so that way I wouldnt be trying to clean and check for any gas-fouled plugs.

So, can anyone think of what may be going on here?

By the way, this is an 88 Accord LX.

Thanks for any help,
Matt

From what I know, 150psi is what the engine should have. Yours is pretty close but kind of low. Oil on the pan can be the oil pan gasket, front and rear main seal on the crankshaft. If it was the headgasket you would notice oil coming from up top.

Quote:

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Originally Posted by Chkn Sanwch

First off, Ill start with my fuel mileage. I replaced the primary and secondary fuel filter last weekend, and Ive put 220 miles on the car with 11.1 gallon fill up, and the needle is getting pretty close to Empty. Obviously there is something wrong with my mpg. This tank also has had a bottle of Seafoam put into it as well.

So, I took my car into my Auto Tech 3 class at my high school, and a friend and I took out my plugs, and checked them, cleaned them, and checked the gap, and put the plugs back in. One of the plugs(on the number 2 cylinder) smelt a little like old gasoline....

So, later that day, I put my car up on the lift to try and weld an exhaust leak, but we needed to take the pipe off to get to the leak a little better, and we were running low on time. I walk over, and notice some oil on my oil pan, and call my teacher over. We look around, and find that the whole pan is slick with a thin film of oil. My teacher said that it maybe a faulty head gasket. We do a compression test, and I got 150, 140, 140, 130(Cylinders 4,3,2,1, respectively...with 4 being on the far left, 1 being on the far right, facing the engine bay). These numbers seem pretty low to me...exactly what should the compression be running at?


Also, Ive noticed a slight waver in my RPM's at idle. They will jump a little low, then a little high. My teacher says it may be a miss in the engine. We pulled plug wires one at a time while the engine was on, and the engine sounded like it was going to crap out with each wire pull(which is good, showing that the wires are all firing properly). My dad is really good and proficient with Honda cars, and he said that I could swap out the Number 1 and 4 plug wires around on the distributor and try to crank the engine over, so that it would blow any crap thats in the carb and in the intake out. Mind you I did this AFTER I checked and cleaned my plugs, so that way I wouldnt be trying to clean and check for any gas-fouled plugs.

So, can anyone think of what may be going on here?

By the way, this is an 88 Accord LX.

Thanks for any help,
Matt

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160 is the New Motor PSI and 120 is the Service Limit, there shouldn't be more then 10 PSI Diffirence between cylinders

Thanks for the input guys.

Now that you have mentioned it, I have noticed a very tiny amount of oil on the lip of my valve cover....just sitting there.

Head gasket maybe?

Valve cover would be the valve cover gasket. Change the gasket and go from there. Headgasket is lower than the valve cover gasket and if it did leak there is no way for it to make its way up to the valve cover.

Have you looked into the carburetor by any chance? Vacuum leaks, cleaning the carburetor out with carb cleaner, things like that.

Quote:

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Originally Posted by Chkn Sanwch

Thanks for the input guys.

Now that you have mentioned it, I have noticed a very tiny amount of oil on the lip of my valve cover....just sitting there.

Head gasket maybe?

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More Likely a Valve Cover Gasket

Head Gasket you'd have less compression and you'd have oil in your coolant and coolant in your oil

Quote:

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Originally Posted by forrest89sei

160 is the New Motor PSI and 120 is the Service Limit, there shouldn't be more then 10 PSI Diffirence between cylinders

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Honda specs for carbureted engines:
171 Max
135 Min
No more than 28 psi difference between any two cylinders.

I wouldn't sweat the 130 number, unless you're itching to rebuild a motor. Just use heavier oil and keep on truckin'.

Not sure about the MPG. How's the car run overall? Any issues?

x2 on the valve cover gasket.

Yea, my bad about the valve cover gasket...thats what I meant to say, I just got the two bass-akwards. lol

But I just had a new timing belt put on, with a new valve cover gasket, and the guy sealed it properly and everything...

I've looked around the carb, and Im not to sure what to look for. From a visual inspection, there arent any vaccum lines with holes or cracks in them. Im going to spray WD-40 or quick starting fluid(because of the combustible vapors) on the vaccum lines while the engine is running, and see if the RPMs raise any.

Like I said, my MPG's seem to be kinda low, any input on that one? 220 miles on an 11.1 fillup(the pump wouldnt let me put anymore in, and the needle was on E prior to that fill up). Im curious to see how far shell go before the light comes on. Ive heard that on these cars, the light comes on when you have about 4 gallons left....is that correct? If so, thatll explain the 11.1 gallon max out. These tanks are 15.9 gallons by the way, correct?

Im gonna try some carb cleaner though to see if thatll help any. Although I did run Seafoam through her very recently.

Oh, and the car runs fine. There is a slight hesitation from a stop when she's first warming up, but thats to be expected though from a 20 year old car like that, right? Other than that, she runs like a champ.