oh bill r, i got a question for ya

[winfred]

i was instructed to replace a engine in a 94 740i, but when i got in it it ran like a top. i was told that the dealer said the 141k mile nic motor was bad but i thought it ran way to good to be crap, i did a leak down on it after the motor warmed up for about 5 minutes and the worst hole was 13%. when it came to the yard a few weeks ago (long term project) the boss moved it around and said it ran like ****, i get into it with a stone dead battery and jump it and it runs fine, my guess is it has one of the common m60 intake problems that pissed off the computer settings and the reset did it good (i've seen it before on v8s), is there something special that i am missing on the leak down test? or did the dealer goober blow it? i am guessing a plugged cat and or a intake leak gave the computer a fit and had it running bad, we had a e38 740 that had a leak and a plugged cat and that drove it nuts, the computer was adjusting the mixture 50% lean on one bank and 50% rich on the other, it wouldn't get out of it's own way but if you unplugged the computer it would do ok for 5-10 minutes. this women is ready to pay for a motor job, i think she's been talked into the nic motor is a time bomb, i just don't think it's bad, i am getting covert pressure from the office to sell the job what ya think?

[Bill R.]

specs on the leakdown allow up to 15% leakdown on any cylinder... If 13% is the max sounds like your still within allowable to me.... I tend to agree with you that its probably not bad and its something else such as the manifold/crankcase ventilation or other vacum leaks is responsible for the poor idle until the dead battery reset the computer back to baseline...
Its ultimately going to be your decision though..... hows that for a copout
answer...





i was instructed to replace a engine in a 94 740i, but when i got in it it ran like a top. i was told that the dealer said the 141k mile nic motor was bad but i thought it ran way to good to be crap, i did a leak down on it after the motor warmed up for about 5 minutes and the worst hole was 13%. when it came to the yard a few weeks ago (long term project) the boss moved it around and said it ran like ****, i get into it with a stone dead battery and jump it and it runs fine, my guess is it has one of the common m60 intake problems that pissed off the computer settings and the reset did it good (i've seen it before on v8s), is there something special that i am missing on the leak down test? or did the dealer goober blow it? i am guessing a plugged cat and or a intake leak gave the computer a fit and had it running bad, we had a e38 740 that had a leak and a plugged cat and that drove it nuts, the computer was adjusting the mixture 50% lean on one bank and 50% rich on the other, it wouldn't get out of it's own way but if you unplugged the computer it would do ok for 5-10 minutes. this women is ready to pay for a motor job, i think she's been talked into the nic motor is a time bomb, i just don't think it's bad, i am getting covert pressure from the office to sell the job what ya think?

[632 Regal]

WInfred, did you do the leakdown test with the pistons at TDC? If they werent you wont get the real leakdown where the Nic blocks fail (you probably know this though). Do the basics on the leak search and go from there. If your being pushed to replace it you will have the old one to sell.

[winfred]

i am just gonna pull the heads when it's out and look for problems, if it's ok a set of gaskets later it'll be for sale

[winfred]

it was a dieing fuel pump, it would only kick out about 30 psi at idle and would drop to about 20 on a rev. i got out voted and we swaped the motor like they wanted, bottom line the bmw dealer choad that "diagnosed" that the nic block was bad can bite my ass, id be happyer if the manager boss and chuck our other mechanic would of taken my word and diagnoses and blah blah blah... whatta ya gonna do!

[Tiger]

so what are they going to do with old motor? Is it just the short block going to be remaining?

[winfred]

we were told to install a alu motor that we had instock, not figure out what the problem was (i hate installing parts on demand, id rather fix the problem) ill clean it up, check it out and sell it, 140k nic 4.0 long block, i did a leak down and the worst hole was 13%, limit is 15%, in it's defence it sat for a month and was run only 5 minutes to drive it into the bay to pull the motor, i noticed how good it ran and did a leak down on my own time to see for myself, if it was warmed up the readings would be even better. i got a look at the dealer procedure for detecting a bad nic and it's useless, they hook the car to the modic computer and look at the readings for each cylinder in terms of spark kv, burn time and injector pulse width, if they see some crazy readings it must be bad. we see these crazy readings all of the time on m60s, it's usually a intake leak, plugged cat, bad coil, crappy fuel system, dead o2 sensor....... bottom line the computer attempts to adapt to the problem and throws the whole motor out of ballence, a small problem snowballs into a car that barley runs, this car had a dead battery and the computers memory was douched so it got a fresh start. the m60 is a good motor but i am not impressed with the injection system or that miserable pcv system

[Bill R.]

it was a dieing fuel pump, it would only kick out about 30 psi at idle and would drop to about 20 on a rev. i got out voted and we swaped the motor like they wanted, bottom line the bmw dealer choad that "diagnosed" that the nic block was bad can bite my ass, id be happyer if the manager boss and chuck our other mechanic would of taken my word and diagnoses and blah blah blah... whatta ya gonna do!