Compression Test Results

[Court M3]

Since my car felt like it was really low on power, I figured I'd get a compression and leak down test to see how things are. Car is 83 323i with just under 87k miles, and regular engine maintenance always performed.

Cyl #1 190 5%
Cyl #2 195 9%
Cyl #3 190 13%
Cyl #4 185 25%
Cyl #5 190 20%
Cyl #6 170 40%

Got the work done at The Werk Shop www.thewerkshop.net and they recommended a complete engine rebuild. What do you guys think?

[Adrian_Visser]

think your shop wants your money. the numbers sure not as high as they could be but its not like one or two cylinders are waay low your lowest is,170 which aint great but its livable. but does it burn oil?

have you done a good tune up on it lately? you know new fuel filter, air filter, run some injector cleaner through, a can of SEAFOAM to remove carbon deposits a valve adjustment etc. it wont be as good as a new engine but itd be better

before you drop the money on a new engine you need to think is the car worth it? how is the body is it rust free? is the rest of the drivetrain in good shape? the suspension? the problem with old bmw's is that the cost of shop repairs quickly eclipses the value of the car. if you dont do your own work and the rest of the car isnt in really good shape then i would say STOP dont dump money into a black hole you can save yourself money now by gettin an e30 in decent shape it will be a whole lot cheaper in the long run trust me.

if you keep the car though it would be cheaper to find a low milage m20 at a wrecker and drop it in there. you would end up with an engine that would probaly outlive your car and would be quite a bit cheaper than a rebuild.

[AdironRider]

Of course the shop says you need a new rebuild, especially when they know the reason your getting the test done is to see if thats really needed. Those numbers dont look god awful, Id try a tuneup first. Make sure you replace the fuel filter as well as part of it.

[PeaveyBassist]

A tune up won't fix compression and leak down numbers. Also, the actual number each cylinder is isnt really important, consistency across the board is whats important. Did they tell you why #6 is leaking? It could be leaking from the rings, valve guide, or the valve seats. It wouldn't warrant a full rebuild but if it isnt the rings, then you might wanna rebuild a head or get a used one to put on. It all depends on how much money you wanna spend on it.

Will

[Adrian_Visser]

true a tune up wouldnt fix low compression but it might restore some of the lost power that made him get the compression test done in the first place.

[Court M3]

yeah replaced fuel filter recently. Cleaned K&N air filter. Sunday I'll change the oil, filter, valve cover gasket, spark plugs, distributor cap and rotor and see where that leaves me.

[Court M3]

still have the same problems. what do you guys recommend now? Maybe checking the rings, valves, and valve seats?

[E30/M30]

Do you use the car mainly for short(sub 5 miles) trips ?

[AdamF 88iS]

Define 'low on power'

If you were having single cylender issues it would run rough or unevenly. Have you adjusted the valves?