Compression test results consultation please

[nariusb]

Hello all,
Hope you've done all your Christmas shopping! Have a great Holiday!
I've done the compression test on my 1989, m20, 525, 130k milesi and not sure how to interpret it. Here's what I've got on the first test:
Cranked 3 times and got around 165PSI, exept the # 6 was 176
I did the test second time to make sure and cranked 6-7 times to maxout the pressure and it showed 185 on 1,5th 180 on 2,3,4 and and 220 on the 6th plug.

Is the compression for # 6, the one closest to firewall, a problem and what kind . Is my compression too high? I could I do to remedy it?
Thanks

[Bill R.]

throttle wide open while cranking




Hello all,
Hope you've done all your Christmas shopping! Have a great Holiday!
I've done the compression test on my 1989, m20, 525, 130k milesi and not sure how to interpret it. Here's what I've got on the first test:
Cranked 3 times and got around 165PSI, exept the # 6 was 176
I did the test second time to make sure and cranked 6-7 times to maxout the pressure and it showed 185 on 1,5th 180 on 2,3,4 and and 220 on the 6th plug.

Is the compression for # 6, the one closest to firewall, a problem and what kind . Is my compression too high? I could I do to remedy it?
Thanks

[nariusb]

throttle wide open while cranking
Thanks Bill, I did. I took the main and fuel relays out and depressed the pedal to the ground while cranking. I also put a teaspoon of oil in first.
The Bentleys are saying it should be142 to 156 after 2/3 cranks. Mine is a bid higher. It would't bother me but the sixth cylinder is higher by 10 PSI after 3 cranks and by 35PSi after 6 cranks.
I also have oil leak somewhere in the area of the sixth cylinder. Could a leak cause this?

[Tiger]

The readings look good... engine in good condition. The sixth cylinder may have carbon deposit due to oil leak... which takes up space in cylinder and causing higher pressure reading. You need to decoke this cylinder and fix the oil leak which is most likely to be cause by valve seals.

[nariusb]

The readings look good... engine in good condition. The sixth cylinder may have carbon deposit due to oil leak... which takes up space in cylinder and causing higher pressure reading. You need to decoke this cylinder and fix the oil leak which is most likely to be cause by valve seals.
Thank you, Tiger
Thats a relieve! Could you specify when you say valve seals, please. Let's say I take valve cover, should I did deaper, what seals should I look for there?

[bullyd]

Thank you, Tiger
Thats a relieve! Could you specify when you say valve seals, please. Let's say I take valve cover, should I did deaper, what seals should I look for there?


part number 19

its a head off job im afraid :(

[nariusb]

part number 19

its a head off job im afraid :(
Thanks again for input. It drives well. Can I keep on driving with the hi 6th cylinder compression or should I fix it promptly. How extensive is the repair?

[632 Regal]

the lash could be off in that cylinder, or excess ould can cause a higher reading from a better seal on the rings.

[bahnstormer]

u could try a leakdown test as well to make sure

[nariusb]

the lash could be off in that cylinder, or excess ould can cause a higher reading from a better seal on the rings.
Hi Regal,
When you say lash could be off, do you mean I need valve udjustment and it would cause higher compression in one cylinder? Should I just follow Bruno's instructions: http://www.bmwe34.net/e34main/maintenance/engine/valve_adjust.htm
Thanks

[nariusb]

Hello all,
Hope you've done all your Christmas shopping! Have a great Holiday!
I've done the compression test on my 1989, m20, 525, 130k milesi and not sure how to interpret it. Here's what I've got on the first test:
Cranked 3 times and got around 165PSI, exept the # 6 was 176
I did the test second time to make sure and cranked 6-7 times to maxout the pressure and it showed 185 on 1,5th 180 on 2,3,4 and and 220 on the 6th plug.

Is the compression for # 6, the one closest to firewall, a problem and what kind . Is my compression too high? I could I do to remedy it?
Thanks
I did the the injection cleaning, using the regulator air hose. Replaced the injectors and the compression in perfect now at 155PSI.
Thanks guys