New 525iT owner! need help with misfire!

[s14brent]

Hi guys,

I just picked up a 2002 525iT that was sitting for 5mo due to misfire. Previous owner gave up on it and sold it for the first cash offer.



First thing after buying it was replacing the dead battery and limping it less than 3 miles home. I pulled the plugs, and there was a mix-matched spark plug on cylinder 4 (culprit cylinder). I had a set of NGK sparkplugs for my e36 m3 next routine maintenance that I swapped in, same problem in idle unfortunately.



The car has some cheap coilpacks so I swapped the packs with oem/bosch from m e36. No change, still has a misfire on cyl 4. I checked the resistance on the cheap coilpacks, all of them were about .8 (which was same results on bosch packs) and wiring on each plug side was reading 12v. No matter what coilpack I put in there, if unplugged while running, there is no change in idle. I went under the cabin filter to the dme and checked voltage at the x60005 pin out 9 (cyl4 ignition coil) and was reading 12v just like the other cylinders read.

I put a screwdriver up to the injectors to hear if I could hear each of them clicking to see if a fuel injector was bad by any chance - nothing wrong there.

Not sure what to check out next. Anyone dealt with similar issues? Would love to get this car running right so I can smog & register it!

Thanks!

[Poolman]

At this point, I would check the compression of the cylinders. Have you checked for spark in # 4 hole? Pull the plug and with it on the coil , have someone turn her over and see if it's firing.Check those 2 things and get back to us with your findings.

- - - Updated - - -

If you find, that cylinder four has low compression numbers, you might try the procedure, that is in the following link. I have used this a number of times, and you need to be careful when doing it, but it is beneficial

https://www.youtube.com/watch?v=_Vo4fm0JDPY

[geargrinder]

Good info from the poolboy. But just because the injector clicks doesn't mean its flowing. Modern injectors are pretty reliable granted, but could still be partial clog. Could try an injector swap and see if the miss moves just to finally line that one out.

Nice looking wagon - nice APEX (I am guessing) on it - did those come with or were those added by you?

[Poolman]

Thanks for the kind words, and too add, it was cylinder 4 that gave up the ghost in my first engine. That engine had 260,000 miles on it, then the exhaust valve went the way of the Dodo. I installed an engine and trans, with 55k miles on them from a wrecked car. Car now has 340,185 miles as of this morning and, still going strong. Adding that, so as to let ya know, don't give up on a nice ride, just because there may be a problem with the engine. As and uncle once told me , when a love of mine had left me, be thank full for Henry Ford,,,there's a new model made every minute, and, that includes engines.

[s14brent]

I had to meet up with a friend who had my compression tester. I will be doing that and spark test later today. I actually believe its a fuel injector issue right now, I tried to go to the local pick-a-part to look for an m54 injector, but all of them were pulled. I did notice that the fuel rail bolts are missing. So it looks like the previous owner pulled the rail also. I may order 6 rebuilt injectors from MEPEH if this is the problem.

If the car has low compression well it will be time to hunt for another m54 I guess. I don't think I'll be getting rid of this 5spd wagon anytime soon!!

The wheels are csl reps I believe. I'll have to pull off the wheels/tires before I can tell you exact brand and size/widths/offset. The previous owner before the last did m5 brakes all around and added the wheels. The front has some gnarly 30mm h&r spacer on there. The guy I bought it from was pretty clueless on mods/maintenance which was scary.

[Poolman]

On the compression issue. Don't sell the piston soak( that is in the link) short. It works , pour a couple of oz's down each cylinder on top of the pistons and let it sit up over night. Also helps to jack up the right side of the car, too make sure the fluid is spread over the entire tops of the pistons and reaches all areas of the piston rings. Then take a vacuum cleaner and hook up something that will reach down into the cylinder to suck up any left over fluid. Try that before looking for a new engine. If it does come down , that you have a complete loss of compression in #4, I suggest that instead of another 525 engine, go with a 530 engine. It will bolt in , without any problems and run. You will need to have the DME reflashed at some point to make it run at it's full potential, but that engine will give you an extra 40 HP and is a snap to have your DME updated to bring the 530 engine on board. Wish I had known how easy it was back when. May do that very thing yet!
One last question, you are, clearing the codes before you try to start the car each time, aren't you ?

[geargrinder]

I did notice that the fuel rail bolts are missing.

Uh oh. Yeah stuff like that... WTF. Missing fuel rail bolts. WTF people.

I'd still do the quick swapperoo off of #4 first to see if that follows, vs diving in for new injectors.

[auaq]

Bet you that the injectors are missing clips too.

[Trainwreck914]

+1000 with what poolman said. My first purchase had a hole in one of the exhaust valves. 30 psi compression. I'm still working on her. But have come along way with e39's. And it also was a 525i. No t. It have purchased 2 more e39'S since. And they're running like champs thanks to this forum. I've rebuilt the head on the 525i and timed it. Just have to bolt it all back up. But it has been a fun learning experience. And these cars are very easy to work on. It's become a drug to me.

[s14brent]

On the compression issue. Don't sell the piston soak( that is in the link) short. It works , pour a couple of oz's down each cylinder on top of the pistons and let it sit up over night. Also helps to jack up the right side of the car, too make sure the fluid is spread over the entire tops of the pistons and reaches all areas of the piston rings. Then take a vacuum cleaner and hook up something that will reach down into the cylinder to suck up any left over fluid. Try that before looking for a new engine. If it does come down , that you have a complete loss of compression in #4, I suggest that instead of another 525 engine, go with a 530 engine. It will bolt in , without any problems and run. You will need to have the DME reflashed at some point to make it run at it's full potential, but that engine will give you an extra 40 HP and is a snap to have your DME updated to bring the 530 engine on board. Wish I had known how easy it was back when. May do that very thing yet!
One last question, you are, clearing the codes before you try to start the car each time, aren't you ?

I did a spark test. Couldn't get a photo of it, but the light emitted normal operation.



Is that (ac delco upper head/fuel system cleaner) available at any local retailers by any chance? (non dealer) It sounds exactly how that guy explained (ringlands stuck inside lands/rings not expanding) - same cylinder and everything! *fingers crossed*

I did a compression test. =X

201
200
203
0
201-202
202

fingers crossed this won't need a swap already!!

thanks for all the help so far!

[justinca540i]

Kinda digging those wheels

Sent from my Nexus 6P using Tapatalk

[Poolman]

The AC Delco product , can be purchased at you local GM dealership, gonna run you about 30 bucks. Hope it works for you. With the good compression that you have across the board , except for # 4, I would run that piston to it's lowest point in the bore , as far as it will go, then pour about 2 ozs in there. Work the crank bolt back and forth a few inches each way, then with the piston still at the bottom, pour 2 more ozs in and then let it sit over night. It's expensive liquid, but it's cheap if it works for you.

[geargrinder]

DOH! Poolboy wins the prize.

Concur with how rock solid the other numbers are.

Not sure if you have access to an inspection cam but I'd stick one of mine in there right away if I was me. Just make sure there's nothing super obvious to be seen.

[golfgod]

I did a spark test. Couldn't get a photo of it, but the light emitted normal operation. Is that (ac delco upper head/fuel system cleaner) available at any local retailers by any chance? (non dealer) It sounds exactly how that guy explained (ringlands stuck inside lands/rings not expanding) - same cylinder and everything! *fingers crossed* I did a compression test. =X 201 200 203 0 201-202 202 fingers crossed this won't need a swap already!! thanks for all the help so far!

If that doesn't get you any compression, do your leak down test...same type of hose for the compression test minus the check(Schroeder) valve...throw air in there and listen where it is coming from.
Expansion tank bubbles=head gasket
Air from the intake = intake valve stuck
Air from the exhaust = exhaust valve stuck
Air from the oil cap = lowers end problem


Hopefully the liquid clears your problem or best case scenario is that you can pull off the head to fix a valve...lower problems means...well, you get the idea..

[Poolman]

Ya know,,just for giggles, pull the disa valve off of that sucker, and see if the pin at the top of the flap is still on there, before you do anything else. If that pin isn't on the DISA valve, I would say not to go another step.

[s14brent]

I finally had some free time today to mess with the car a little more. I initially ordered the ac delco product off amazon, but 3 days later (still hadn't shipped) I decided to cancel it. BMW had a similar bottle for $28.



unfortunately no such luck after about 2oz being dumped in within 24hrs, but now I'm thinking it may be a stuck valve because even though there is 0 compression still, I did a leak down test and it is holding at close to 10% and the only air escaping (which doesn't sound like much) is from the exhaust. I will probably do this test again tomorrow to make sure I was at proper compression stroke TDC on the cylinder. It was kind of hard to turn the crank by hand while checking piston height.



I have not pulled the disa valve yet, I will get to that, but there isn't any rattle/noise coming from there at the moment. Is it possible to just have a stuck valve? I wonder if a seafoam treatment might be something to try

[blarf]

Anything is possible... but what about a stuck lifter?

[golfgod]

Sounds like you're on the right track and have the right testers, etc. yeah, pretty important to have that cylinder at TDC lol...make sure you test the intake stroke as well, and that air should come out of the intake...I guess I'm stating the obvious because it sounds like you understand the process.
You can turn that Jesus bolt back and forth once you are "close" to TDC, just don't make a habit of turning that motor backwards too much...a little bit to do this test won't hurt at all.
Next post refers to a stuck lifter and could be plausible, but I would think the noise would be immense.
The sea foam treatment is another option and a good idea since you've got that cleaner in there already. That should also clean those lifters too. That requires you to run that motor quite a bit and at hot temps too so be diligent when you do that. Once you've done that, change that oil and filter. Then run the motor some more before you do your leak down again. You gotta get all that crap out of there.
Stay diligent on these tests because that's your last option before removing/fixing/replacing the head or motor.
Good luck and report back!

[auaq]

You could if you want remove the valve cover and observe if the lifter is sticking or not when you turn the crank over, but yeah try to get that cylinder at TDC first and then redo the leak down test once more to make sure none of the valves are still open.

[s14brent]

i tried a leak-down again on both intake/exhaust stroke (both at TDC) and yield same results. Will be doing the seafoam treatment LATE at night so I don't piss the neighbors off. I'm going to LA this weekend but will have to look at options when I get back whether it's pull the head or maybe I can source another m54b25 or a m54b30 for the same cost :



I'll chime back in post seafoam, but I kind of doubt it will fix this problem.

[Poolman]

That seafoam stuff , is what the Trump guy talked about grabbing, next to the AC Delco product. I would remove the valve cover and see if you can tell if the lifter is moving, or if it's stuck. If it's moving (exhaust valve) then you have to remove the head , to make the fix. Have you removed the DISA valve to inspect it yet, as mentioned in my last post? If the pin is missing from it, you needn't look any further for the problem.

[s14brent]

That seafoam stuff , is what the Trump guy talked about grabbing, next to the AC Delco product. I would remove the valve cover and see if you can tell if the lifter is moving, or if it's stuck. If it's moving (exhaust valve) then you have to remove the head , to make the fix. Have you removed the DISA valve to inspect it yet, as mentioned in my last post? If the pin is missing from it, you needn't look any further for the problem.

the ac delco product is just so expensive to blow all at once!! I plan on removing the valve cover and inspecting maybe next week after I get back from a quick trip to LA. I removed the DISA valve earlier. Looked really good, o-ring still had the groove and pin was in-tact so it was probably replaced not long ago.



i also got locks for my rack.....since this one is parked outdoors atm, I also replaced the ground cable from engine to chassis, since the original was in bad shape. baby steps.

[Poolman]

That cleaner you bought from BMW, is the same stuff as the AC Delco product,,just under a diff label. Sounds like your exhaust valve has given up. Hope that it's something like a lifter, or maybe a broken spring. When mine did this , a used engine was cheaper that making the fix of a valve replacement. Tools that you need to do the job, aren't cheap. Might be able to rent them somewhere though. That's a fine looking ride, hope that you save her, they are hard to find.

[auaq]

Okay, I'm confused a little here.

What do you mean when you say you did leak down test on "intake" and on "exhaust" stroke?

[s14brent]

That cleaner you bought from BMW, is the same stuff as the AC Delco product,,just under a diff label. Sounds like your exhaust valve has given up. Hope that it's something like a lifter, or maybe a broken spring. When mine did this , a used engine was cheaper that making the fix of a valve replacement. Tools that you need to do the job, aren't cheap. Might be able to rent them somewhere though. That's a fine looking ride, hope that you save her, they are hard to find.

I figured another motor might be worth looking at just for cost efficiency. I would like to do m54b30 swap, but I really should save that cash for taxes right now. Maybe if I can find a clean one at the yard I will bite the bullet. I think the car will be on hold until I can free up some cash to dump at it. I appreciate all the help so far!

Okay, I'm confused a little here.

What do you mean when you say you did leak down test on "intake" and on "exhaust" stroke?

I meant "compression" and exhaust stroke. I was doubting my first test being at TDC and I just had to double check results.