Life does suck with rough idle/missing

[busafreak]

'96 ti.
Rough idle feels like its missing. Exhaust has a puff puff puff sound. Things done:
New ccvv
Replaced cracked icv
New plugs
New wires
New coil pack. old one had cracks
Replaced all vacuum lines.
Cleaned maf
Intake tube recently replaced.
Cleaned throttle body.
Compression is good:
#1- 130
#2-150
#3-150
#4-140
Removed fuel rail and inspected injectors. Screw driver to ear while running and they sound healthy.
Fuel filter replaced 10k miles ago
Valve coVer gasket replaced 10k miles ago
Plugs are not fouled, nice even color on all of them, no oil. New Ngks

One would think it should be running like a nice expensive German watch... Huh?
No cels, and it runs really good. Just idles like crap and its driving me nuts.

Haven't changed camshaft sensor. Probably should of test it while I had the upper intake manifold off. Btw, I plugged that stupid tree vacuum design they did for the injectors. What a dumb idea.

Anyway, any ideas?

Picture of the front that I just got painted. For your viewing pleasure. Yeah, looks good but runs like crap.. ayy priorities..lol.

[busafreak]

No one? Not even a go f yourself? Lol <---Cmon that was funny.

I'm on info overload. Reading about cp sensor, dme, ews2, dme relays, geez! I guess instead of throwing parts at it I should just find a place to plug it in and do some diagnostics.

You know, the reason for me getting this car was to work on it. Sort of as a stress reliever after work. Lol yeah..

[UberWagen]

Rather than a super long paragraph, I will just kind of bullet some stuff.

1st, have you actually tried to pull codes out of it and what octane fuel are you using? Regardless of no CEL.

-How did the injector o rings look? Can be a source of a large vac leak
-Did you check the vac lines on the fuel rail tree?
-What condition is your air filter in? A plugged one would choke the engine
-If you have access to a scanner, check your O2 sensor voltages, make sure they're swapping and not stuck.
-Is your oil and coolant clean, not milky?
-Just because you cleaned your MAF, that doesn't necessarily mean it works right. When you get hold of a scanner, check out your MAF readings.
-Do you have good fuel pressure?
-Are your coolant temp sensor numbers accurate?
-Does your secondary air pump have a vac leak?

[busafreak]

The injector o rings looked good. I sprayed th cleaner around them while engine running and no change. I have not checked fuel pressure. Good point.
-I replaced the hoses to injector vac lines. I then eliminated that tree. Same results both ways.
- Filter is a new K&n stock replacement.
-I don't have access to a scanner. Would help me out if I did have one to see what's going on.
-oil is not milky, coolant is clean. Have not tested coolant sensor.
-maf was replaced not long ago. But it is a possibility.

Secondary air pump? That's the thing with a vac hose coming from the th right? I replaced that hose..

Yeah, I'm thinking I should get something to scan my engine to see what's going on before I attempt anything else.

[UberWagen]

Secondary air pump? That's the thing with a vac hose coming from the th right? I replaced that hose..


Right, but the actual rivets holding the pump together can break and cause the pump not to seal right. I had to put some allen bolts in mine because it was leaking around the brim. The part the hose connects to is the top of it, which is riveted to the whole pump is self. I don't want to send you on a goose chase, but it's worth a look.

I also don't want to say it's your headgasket because you checked compression and your oil and coolant looks fine, but I just did a headgasket on my Ti. It started out as just a putt putt symptom like yours at start up because coolant leaked into the cylinder by a crack in the water jacket part of the gasket, but eventually it cracked further and I lost so much compression I couldn't even start it.

Before you even consider that though, get a hold of a scanner. It's worth it. It's a big initial investment, but get a good one. Mine has actually made me money, and I can do Emission checks, Freeze frame, live data, Mode 6, etc. http://www.amazon.com/Actron-CP9175-...eywords=actron
Similar to that, but mine was less expensive when I got it. Somewhere around $130.

[busafreak]

Man, I hope its not the head gasket. I have to go look at my records I have for the work done to it, but I think it has been replaced along with all the cooling problem parts including the radiator.

You know I was looking into getting the das interface connectors and run dis and inpa and get more in-depth. But the info with software and running issues are kind of sketchy with all the issues. But looks like once you get it running you can do some neat things and test more modules than just emissions stuff.

But that takes time and the scanner you posted is instant. Although I don't drive this car much.

[6speed ti]

If the rough idle is only at idle then check the oil filler cap seal and the oil dipstick orings. A slight vacuum leak will give you a rough idle but it will run fine at higher rpms. Do you have any oil leaks from the front or rear main seals?
That is a source of losing vacuum at idle as well.

BTW: You mentioned you have a 96 TI. No secondary air pumps on the 96 TI's
The secondary air pumps were installed on models built from January 1997 and on. I know because my 97 TI was built in October 96 and I have no secondary air pump installed. The service manuals and electrical schematics confirm this.

[busafreak]

Thanks for the tips 6speedti.. I changed the dipstick o rings and fabricated a home made smoke tester that works very well. Found smoke coming out of the DISA, the intake tube and a hairline crack on the icv.
The intake tube was leaking where it connects to the tb, tightened the worm clamp up and fixed that leak. Lol.. Took off the DISA and changed the o ring and a couple of vacuum tubes that are on it. Those had very obvious cracks. What a stupid design. Cleaned it up and re installed. The icv I siliconed the hairline crack. Picked it up used from a member here since it was better than the original that was on the car. But I will have to pony up for a new one.

I did a smoke test again after doing those things and no smoke leaks but I still have rough idle. I have not gotten under the car to check for leaks yet, so I have to do that also.

I hooked up carsoft and had no codes other than an air bag code. Learning easydis and I almost have that working with the interface cables.

One thing I did notice is that when I take off the vacuum hose that's going from the tb to the fuel pressure regulator at idle, the idle stays the same. Does not change one bit. Past experience tells me this is wrong. Aren't the rpms supposed to rise when disconnecting that hose? I don't have much BMW experience, but I think I'm right.

[6speed ti]

Glad you are chasing down the leaks. I have a rough idle from vacuum leaks as well. I found and can hear it from the Crankcase ventilation valve as well as the seal between the two sandwich gaskets between the upper and lower intake manifold. Not sure if it is both or one. I can reseal the valve but the plate gaskets need to be replaced to do it correct. I had a bad front main oil seal leak. It created a very rough idle and it was squealing like a fan belt but it was the air sucking in past the seal. I changed the seal and it cleared up. No oil leak and a much better idle. If you disconnect the FPR hose the idle should not change much. It is such a small opening. Mine does not. The smoke test is good if you can not hear the vacuum leak. I can hear it hissing up close.
I have one more oil leak to take care of. It requires dropping the transmission. Rear oil seal. Hopefully it will not get to the point the front one did. Not ready to drop the transmission and replace the clutch while it is out.


334,000 miles and counting.

[BlackBMWs]

Originally Posted by UberWagen

It started out as just a putt putt symptom like yours at start up because coolant leaked into the cylinder by a crack in the water jacket part of the gasket, but eventually it cracked further and I lost so much compression I couldn't even start it.

Same for me after overheating last year.

[IronBMW]

My 99 318ti, M44, It has same problem above, engine has something like a missing
Before I do all the items below, I cleared ECU codes, start the car and scan it again, no fault codes. After that

I replaced:
spark plugs, new
Crank Case Ventilating Valve (CVV), new
Secondary Air pump and its O ring, used, (O ring, new)
Breather hose from Rocker cover to CVV
both gaskets that between the top and the bottom parts of Intake Manifold
Mass Air Flow Meter (MAF), used, (in fact, I got 2 used one and I tried both)

I cleaned:
Throttle body valve, there was nothing really to concern
Idle Air Control Valve (or Actuator) (IAC), there was nothing really to concern

I checked:
Ignition Leads
Engine Cap
Engine Dip Stick (O ring)
Injectors O ring
Vacuum hoses, I think all of them
Rocker Cover Gakset

the engine still like it has missing, but with this missing RPM is not changing. It is between 700 and 800
I have slightly engine oil leaks at the Rear Crankshaft Seal

[6speed ti]

Originally Posted by IronBMW

My 99 318ti, M44, It has same problem above, engine has something like a missing
Before I do all the items below, I cleared ECU codes, start the car and scan it again, no fault codes. After that

I replaced:
spark plugs, new
Crank Case Ventilating Valve (CVV), new
Secondary Air pump and its O ring, used, (O ring, new)
Breather hose from Rocker cover to CVV
both gaskets that between the top and the bottom parts of Intake Manifold
Mass Air Flow Meter (MAF), used, (in fact, I got 2 used one and I tried both)

I cleaned:
Throttle body valve, there was nothing really to concern
Idle Air Control Valve (or Actuator) (IAC), there was nothing really to concern

I checked:
Ignition Leads
Engine Cap
Engine Dip Stick (O ring)
Injectors O ring
Vacuum hoses, I think all of them
Rocker Cover Gakset

the engine still like it has missing, but with this missing RPM is not changing. It is between 700 and 800
I have slightly engine oil leaks at the Rear Crankshaft Seal

Did you check the vacuum at idle?
It should be about 18 inches of mercury on the vacuum gage.
If the rough idle is only a problem at idle and there are no other rpm or performance issues above idle like a miss in the cylinders from a bad plug or ignition miss chances are you have a vacuum leak. With a vacuum leak that affects idle only it is slight enough that the engine overcomes this at higher rpm's. If it is only a idle problem then address it as a idle only problem. Do not chase this as a all around rpm range problem. It will drive you nuts not to mention drain your wallet.

[IronBMW]

Thank you for your quick reply.
My car has 15 to 16 inch of Mercury (50 KPa to 55 KPa). I check another car (98 318ti) same symptoms, vacuum pressure was 14 to 15 inch of Mercury. I checked here and there but still I can't find any vacuum leak, any idea please?
This is next day, I am working now with 98 BMW 318ti which reads 14 inch of mercury (40 KPa), I found the connector to Injectors was broken, replaced that one, no change at all. I did smoke test, slightly smoke comes from Crank Case Ventilating Valve (CVV) from its O-Ring, I changed its O ring, Vacuum pressure has changed from 40 KPa to 50 KPa, but still shaking, I don't know where shall I look? any idea? I am sure there is something related to this problem because many many 318ti has same problem.

[busafreak]

Mute it so you don't have to listen to my compressor or me blowing the smoke away. https://www.youtube.com/watch?v=qdgK...e_gdata_player

Update on my particular problem:

Did another smoke test and even after replacing the vacuum hoses on the disa, found more smoke. Took it off again and noticed there is a small hole where the smoke is coming out of. Upon further inspection I noticed the orange diaphragm inside the valve is damaged. I'm assuming that hole (orifice) is for vacuum to escape once the butterfly valve opens or closes. But I'm sure the diaphragm is the reason for there being a vacuum leak.

Research on faulty diaphragm on disa valve explains the same symptoms I'm having. Rough at idle, and missing like its running on 3 cylinders at idle but runs fine.

So to test, I siliconed the crap out of the orifice and will leave the 2 pin connector unplugged so that the valve does not close. Waiting for silicone to dry. I have to wait for a new one, so why not mess with it..

[IronBMW]

I hope you will get a good news after put silicon. I already replaced Disa valve with anoth used one, but same, and I know 2 cars now (as well as my car) both are BMW one is 1998 and the other is 1999, both they have same problem exactly. I took my 99 BMW 318ti to an auto electrician before 2 days ago, but didn't hear from him yet, I think I will check with him this afternoon, and I will let you know of course.

After 7 days stayed at this auto electrician, he replaced Camshaft sensor and Oxygen Sensors, both are new, cleared ECU. He also did a smoke test and his normal checking, he said that he checked it by scope, all signals were fine, but at the end still has same symptoms, the ugly missing or hissing or jerking or whatever you want to say.

I will arrange to take it to BMW specialist to check it.