Compression Test - Is the BMW Engine any good?

Compression Test. Is the BMW Engine any good?
Today we continue our search to find out why the 1984 BMW 733i runs so badly. We try our hand at a compression test. I lso show how to do a lash adjustment on this M30 engine. What does it tell us? Am I just in Total denial? ....

[@projectv12bmw66]

Another great one!

[@fortheloveofcarz]

Thanks!

[@Wil-70-NL]

These engines suffer when they have vacuum issues. Valves that are ticking are normal. I always would give it a good service, fuel injector cleaner, new fuel and air filters, etc. Then drive the car for couple of hours and blast the beast to it's limits to burn the carbon. We have the possibility in Germany to go full speed. After that test run day it will drive a lot better. Some fine tuning and it's ready. Bmw's don't need so much attention.

[@fortheloveofcarz]

As I go through the process I definitely learn the vacuum thing. :-)

[@kellyanderson7115]

I just did a boroscope/compression test of a 2001 330xi with 132K miles. The cylinders look awesome using the boroscope - nice crosshatch all the way up and down the cylinders. The compression check had four cylinders at 185PSI and two at 187PSI. It doesn't get much better than that!

[@fortheloveofcarz]

Thats awesome!

[@drclemthesim]

Awesome video bmw always fun work on

[@fortheloveofcarz]

seems fun now. lol at the time I was pretty green and scared of the whole process. lol

[@drclemthesim]

It just all the sensors and computers that make it worse when you break it down it all same me myself I love old Toyotas like my 83 tercel sr5

[@hosea5259]

how did you make the button for the OBD port, really smart idea

[@fortheloveofcarz]

Wish I could take credit but I saw it on a forum somewhere.

[@danforthe2006]

When mine came out of 16 years in a barn, it had great compression in 1,2,5 and 6. 3 and 4 were mid 90s (GAAAHHH!!!!) but a little Marvel, just a little, and a quick crankover, then left for a day or two, started to make an improvement. Up some, but still below what you'd want. My old faithful tech got out his boroscope, and confirmed it was the valves on 3 and 4 not seating properly, not closing the whole way, and due to the resulting poor seal, lowering the comp. Solution? Just drive the excrement out of it for a week and take new readings. Oh, and another shot of Marvel in the offending pots. Lack of use caused it, and just using the car solved it in the end. So, go drive the crap out of that Seven! Dan in Bangor P.S. Can't wait to hear it after valve adjustment........ P.P.S. When the vales are sealing right, it changes the gap, so......

[@fortheloveofcarz]

I wish to god the valve adjust had fixed it :-)

[@danforthe2006]

@@fortheloveofcarz I think you just need to put some miles on it under varying conditions and see if that settles things down. Marvel Mystery Oil is a truly marvelous substance! Just a capful, though, in each pot, crank a little without starting it, then let it sit overnight. As we say in Maine, "BINGO!" Dan