I’m going to replace all the rubber seals on the valve cover bolts. I’m wondering if one of those could be the culprit.
For it to run that bad wouldn’t it have to be a large vacuum leak?
The last experience I had with a Chrysler V6 was a 4 inch long hose, about a 1/4 inch in diameter with a dry rot crack along the side, caused all sorts of spitting, stalling and sputtering.
To date I have replaced every hose on the engine, every gasket. At this point the problem is not a vacuum leak. I took it to a guy who repairs BMWs. He told me its either the head gasket, the head (antifreeze causing misfire), or a bad fuel injector(s) fouling out the plug(s). The head and head gasket were just replaced, so I’m hoping to rule those out. I’m leaning toward a fuel injector. I was just tinkering with the engine and cylinder 5 was not firing at all. I pulled the coil and tested it for spark. It was in 100% working order. I even swapped it with another working coil to be sure. When I unplugged the coil on cylinder 5, the engine ran the without change, meaning the injector must be fouling out the plug. All of the injectors spray fuel. I replaced the plugs also, I have 2 new sets, so the plugs are not the problem.
To date I’ve replaced:
spark plugs
Both pre-cat 02 sensors
valve cover gasket set
all vacuum hoses
hose from intake boot to ICV
intake manifold gaskets
MAF
all new hoses/hose clamps and connector on M50 intake
New o-rings on fuel injectors
head
head gasket set
That’s all that really relates to the misfire problem, that I can think of.
Does anyone have any E36 fuel injectors they are willing to sell? I’d rather replace the injectors before I tear the engine apart to replace a leaking head gasket again.
Plugs will tell you if it’s antifreeze.
Have the guy pressure test the cooling system
I may have a single stock S52 injector here you can have. Will have to check later.
swap the number 5 injector with another one that doesn’t currently have an issue…
:thumbup:thumbup
Thanks again Adam! I just checked the resistance on all of the injectors with my multimeter. They all read .015 Ohms. The pintle cover was cracked/broken on injector #5. I wonder if this affected the spray pattern caused the plug to foul?
I’ll try that tomorrow morning. Thanks.
Absolutely will
I have ONE purple top S52 injector here. I’m not 100% certain of it’s condition, but it’s 100% intact and you’re welcome to it if you’d like it. I will be at the machine shop tomorrow morning and will bring it with me and If I leave early, I will have it sitting there for you.
I also have seven FMS 24lb(blue top) injectors that will fit the rail. They’re a bit larger flow rate than your stock ones(~21.5lbs/hr) but will run the car for testing. Good for cammed cars. Were the secondaries on my old 8 injector setup on the dodge. Low mileage and GC, $50 for all seven.
I’ll take all seven off of your hands. After closer inspection, most of mine need to be reconditioned anyhow. I can make it down tomorrow morning if that works for you.
This car is going to have one refurbished motor after this :rofl
The 24lb’ers will run the car, albeit a little bit rich as they’re a couple lbs/hr more in flow rate than the stock injectors.
I’ll swing by your shop wednesday morning. I’ll at least pick up the S52 injector for now. I couldn’t make it down that way today, had some stuff come up.
I will be there tomorrow from ~9am to 1pm or so and have the S52 injector in the truck.
I think I’ve got this narrowed down. I just swapped out a bad fuel injector, which fixed that problem, but the random misfires continue. I let the car run for a bit today. There was quite a bit of white smoke, not overwhelming, but enough to catch my attention. After about 30 min of running the temperature started to rise just above normal operating temperature. I shut it off and let if cool off. I checked the antifreeze, after just bleeding the system, and it was low. There are no leaks. It must be getting antifreeze in the cylinders to cause the misfires. At this point the head or head gasket is bad. Which brings me back to square one when I started this project. I don’t really feel like tearing this thing apart again. Would a compression test confirm my suspicions? I believe the head gasket may be shot as a pulled the original head then removed it to put the replacement head on. The gasket was new so I reused it after I torqued it down.
Borrow a tester that would test the coolant for presence of exhaust gases to be certain.
I might grab mine if I’m at the garage any time soon.
The head pressure tested 100% but I remember you said you reused the headgasket when you picked up that injector.
Have you had the cooling system pressure tested for leaks yet? that is the ONLY surefire way to diagnose a HG leak without just replacing the gasket.
Also have you had the system code read with a proper BMW tool yet? Clark has stated it before about basic read errors and he is 100% right.
FWIW, An exhaust system that went through an HG leak will contain copious amounts of coolant that can take quite a few hours to dissipate(white smoke), and the drastic drop in coolant level can be related to an vapor lock release in the system after the thermo opens. Not disputing your findings, just advising the common alternative cause to both.
How are you bleeding the coolant system on the car, because these things are notorious for getting and trapping air in the system. If you are not pressure bleeding the cooling system, the nose of the car really needs to be high, RPMS kept up around 1500-2000, and constantly monitor fluid levels in the reservoir as the temp rises. Get the nose of the up on jackstands is the preferred procedure(rear chocked and on ground)
What head stud torque procedure did you follow?(list your specs here) and you did use NEW headbolts right?? They are a one shot deal and must be replaced every time the head is removed or you will never get a proper seal. Proper sequence with lightly oiled bolt threads and washers is 30nm pre-torque through sequence, 90 degree yield through sequence, then another 90 degree yield through the sequence. After they go through that sequence, the bolts are stretched and cannot be reused again.
Can you pull the spark plugs out and take a clear picture of each(label each one to it’s mated cylinder)? Spark plugs speak mountains on basic internal diag on these terms.
I’d love to be able to pull this car in for you and just run the diags but I’m a bit tied up at the moment and won’t have any free time for a couple weeks to pull away for a day and check a few things out. If you can hold out for a couple weeks on this I can do all of the above.
I think the head is fine. I did reuse the head gasket, I’ve gotten away with it on other vehicles.
I haven’t had the cooling system tested.
The garage I took it to, to have the codes read had the tool. It looked like the board UPS drivers use, it plugged into the port in the engine bay. He wouldn’t tell me exactly what it said. I believe he wanted me to leave the car at his shop so he could do the repair. He just said it was related to the head/head gasket.
It did have a vapor lock because the heater would blow warm then cold air. I raised the overflow bottle about a foot above the engine to get the air out, it was on wheel ramps. I did not rev the engine to 1500-2000 rpms.
I used new headbolts which I lightly oiled. I did exactly as you stated in the older post. I also used the Bently manual for the proper order/tightening sequence.
I will take the plugs out tonight and get a photo of each one, probably within the next hour.
I’ve waited 3 months with this car so far. I’m willing to wait a little bit longer if you can look at it for me. You’ve been a great help in this learning process for me.
I just did a compression test…here’s the amazing results:
Cylinder#1: 67 psi
Cylinder#2: 72 psi
Cylinder#3: 75 psi
Cylinder#4: 64 psi
Cylinder#5: 85 psi
Cylinder#6: 68 psi
Here’s the pics of the plugs:
#'s are all stupid low.