Urgent Help Needed

[Faheem]

@Andy McDonnell Hi mate, thanks. I believe that the plugs are in okay now, one of the very first things I did after buying my zed was change the plugs, at the time my mechanical knowledge was poor (it's still not brilliant but definitely far better than it was), anyway to cut a long story short, I think I didn't tighten them down properly.

I took them all out a couple of weeks ago after the incident where the plug shot out, examined all of them and put them back in tightening all of them properly this time. The threads on the plugs were fine and didn't appear to be damaged.

Should the problem not correct itself then I think next on the list is a new coil pack. But for now let's hope for now that the sensor is the only offending item.

 

[andyglym]

@Andy McDonnell Hi mate, thanks. I believe that the plugs are in okay now, one of the very first things I did after buying my zed was change the plugs, at the time my mechanical knowledge was poor (it's still not brilliant but definitely far better than it was), anyway to cut a long story short, I think I didn't tighten them down properly.

I took them all out a couple of weeks ago after the incident where the plug shot out, examined all of them and put them back in tightening all of them properly this time. The threads on the plugs were fine and didn't appear to be damaged.

Should the problem not correct itself then I think next on the list is a new coil pack. But for now let's hope for now that the sensor is the only offending item.

OK mate, worth a shout, good luck with solving the issue mate

 

[Faheem]

Unfortunately the problem is still there, the car started first time today, however, the idle was still rough.

What to do now? Change the coil pack?

 

[Tracy Dee]

Have you changed the idle valve? Sorry if you already have.
Mine all of a sudden last year got really lumpy rough idle barely ticked over .
Cliff tried an idle valve and gasket he seemed to think it was the gasket as it fell apart.
He could hear air noise around valve.
Anyway changed both after a run idle back to normal.

 

[colb]

Good idea from Tracy regarding the idle valve maybe a bit sticky and in need of a clean.
Item 9 is the valve on the M44
http://www.realoem.com/bmw/enUS/showparts?id=CH72-EUR-08-1998-Z3-BMW-Z3_19&diagId=13_1733

If that doesn't solve the rough idle then check out the exhaust manifold for cracks that may be the cause, when the car is warmed up how is the idle then? Cracks in the exhaust manifold may seal themselves as they get hot and mask the cause.

 

[FRANKIE]

View: https://youtu.be/aqo8_hI8zXE


This is what the car is like on a cold start. Today morning it stalled twice - - as you can see in the video it stalls within the first couple of seconds. After about a minute with the engine running the misfires disappear and the car is smooth to drive with no other hiccups.

I don't like creating too many different threads and as this is a misfire issue I feel like it should be posted here.

Only codes I'm getting are:
Misfire in multiple cylinders
And a P0130 which I believe is for the o2 sensor.

Cam sensor was replaced last year but @Brian4 did point out that if this was cheap then it may be failing again.

Just wanted to get some more thoughts and opinions on what the issue maybe?

I have not really been following this thread as I can't give the forum as much time as usual. I just listened to your video of you starting the car. When you are cranking the engine, I can hear a cylinder being missed with regard to compression. When the starter cranks the engine, it meets resistance at each compression stroke of each cylinder and gives an even sound as each cylinder contributes its resistance to the starter. In your case, one cylinder is not offering any resistance to the starter and hence the 'skip' in the sound of the engine cranking. Something is allowing compression to escape, or not allowing compression to build up during the compression stroke. More often that not, it has to do with valves or head gasket but there are other possibilities. Frankie

PS. If I were in your shoes, I'd go out and buy a compression tester. They are not expensive. Remove all your spark plugs. Connect the tester to one cylinder at a time and look at the readings. The reason for removing all the plugs is to let the engine to turn over easily without the compression of the other three cylinders interfering. You might need another person to crank the engine but you can really do it yourself. After you attach the tester into one plug hole, you can crank the engine yourself and the tester will register and hold that reading of the amount of compression for you to read. You can crank it through several cycles or for several seconds. When you're done cranking, go to the engine compartment and look at the tester. I don't know what the optimum pressure is for your car but I think it should be at least 150 psi. @t-tony can tell you how much to look for. I already know the results of the test as I can hear it in your vid. Frankie

 

[t-tony]

I have not really been following this thread as I can't give the forum as much time as usual. I just listened to your video of you starting the car. When you are cranking the engine, I can hear a cylinder being missed with regard to compression. When the starter cranks the engine, it meets resistance at each compression stroke of each cylinder and gives an even sound as each cylinder contributes its resistance to the starter. In your case, one cylinder is not offering any resistance to the starter and hence the 'skip' in the sound of the engine cranking. Something is allowing compression to escape, or not allowing compression to build up during the compression stroke. More often that not, it has to do with valves or head gasket but there are other possibilities. Frankie

PS. If I were in your shoes, I'd go out and buy a compression tester. They are not expensive. Remove all your spark plugs. Connect the tester to one cylinder at a time and look at the readings. The reason for removing all the plugs is to let the engine to turn over easily without the compression of the other three cylinders interfering. You might need another person to crank the engine but you can really do it yourself. After you attach the tester into one plug hole, you can crank the engine yourself and the tester will register and hold that reading of the amount of compression for you to read. You can crank it through several cycles or for several seconds. When you're done cranking, go to the engine compartment and look at the tester. I don't know what the optimum pressure is for your car but I think it should be at least 150 psi. @t-tony can tell you how much to look for. I already know the results of the test as I can hear it in your vid. Frankie

Hi Frankie, I was having similar thoughts but decided to await the result of the sensor change. I would go along with a comp. test as a next step. I was wondering if there is, a) a sticking valve (unlikely) or b) a cam follower (hydraulic tappet) losing its oil over a standing period.

Tony.

ps. Regards the psi you might expect I would say 150-160 would be acceptable, but the main thing is that they are relatively equal to each other across the 4 cylinders.

 

[oldcarman]

Totally Agree about the cylinder pressure dropping, it was my first thought upon hearing the car starting. Good pick up @FRANKIE. Definitely get the car pressure tested as either you have a weak valve lifter as @t-tony suggests which pumps up again as it warms and receives oil under pressure or as @colb suggests a cracked exhaust manifold. If it is a valve which is unlikely or poor compression rings on the piston you can determine which by introducing air through the spark plug hole and listen which direction it goes!! If you hear it in the oil pan it's rings or a piston cracked. If in the valve cover it's in the valve train. Try each cylinder till you find the culprit!! HTH JIM

 

[Faheem]

Thanks all, you've all provided me with some fantastic suggestions and I'll keep them in mind. Trouble is, rather than replacing each part once at a time and ending up with a rather large bill I'd much rather find the offending item and fix it.

@Tracy Dee Thanks! I have not, I may attempt this in the future if the issue persists and I can't get anywhere with the diagnosis.

What concerns me is that a car that has only done 71000 miles should not really be getting these issues. I suppose the car is fairly old though. Also, despite being a daily driver, it gets taken good care of, regular service (every 5k miles) and a good fuel additive once a month.

Only thing I haven't done is change fuel filters, I went and bought a new fuel filter but ended up fitting it to my project zed as that was running without a filter!?

@FRANKIE @t-tony In regards to the long crank, that is not a daily occurrence. Despite it being cold today in the morning the crank was fine yet once the engine had started there was a misfire when the accelerator was pressed down BUT the car didn't stall and after about 20 seconds the misfire had gone and the engine was running correctly.

What is surprising is that since resetting the stored codes for the misfire -- did this after installing the new cam pos sensor -- they have not come back. Again it's too soon to tell as the codes may come up tomorrow. It's a shame that my car does not have a CEL as I never know when the codes have been stored.

I may purchase a compression tester and if I do I'd like to know when I should test the compression in each cylinder - should it be when the engine is cold - or when it's running at temperature - or both?

 

[Faheem]

@oldcarman Thanks Jim!

 

[t-tony]

Thanks all, you've all provided me with some fantastic suggestions and I'll keep them in mind. Trouble is, rather than replacing each part once at a time and ending up with a rather large bill I'd much rather find the offending item and fix it.

@Tracy Dee Thanks! I have not, I may attempt this in the future if the issue persists and I can't get anywhere with the diagnosis.

What concerns me is that a car that has only done 71000 miles should not really be getting these issues. I suppose the car is fairly old though. Also, despite being a daily driver, it gets taken good care of, regular service (every 5k miles) and a good fuel additive once a month.

Only thing I haven't done is change fuel filters, I went and bought a new fuel filter but ended up fitting it to my project zed as that was running without a filter!?

@FRANKIE @t-tony In regards to the long crank, that is not a daily occurrence. Despite it being cold today in the morning the crank was fine yet once the engine had started there was a misfire when the accelerator was pressed down BUT the car didn't stall and after about 20 seconds the misfire had gone and the engine was running correctly.

What is surprising is that since resetting the stored codes for the misfire -- did this after installing the new cam pos sensor -- they have not come back. Again it's too soon to tell as the codes may come up tomorrow. It's a shame that my car does not have a CEL as I never know when the codes have been stored.

I may purchase a compression tester and if I do I'd like to know when I should test the compression in each cylinder - should it be when the engine is cold - or when it's running at temperature - or both?

Well worth doing both to compare Faheem, but careful with hot plug removal.

Tony.

 

[Faheem]

So. Before doing a compression test I thought to myself that it may be worth trying another set of Ht leads and another coil pack, however, this hasn't improved the rough idle, if anything it's made it worse.

I also swapped the icv from the project car but still no difference.

I inspected the rubber boot going from my air filter to the upper manifold for cracks but none exist, I did wreck the jubilee clip though as I overtightened it and broke it.

The vacuum hoses under the manifold have been replaced.

Maf sensors have been swapped.

I suppose it's good that I have two cars with identical engines as I can keep swapping things until the problem goes away but it's definitely not ideal. Very time consuming especially when waiting for the results.

Only thing I haven't tried is to swap out all 4 of my spark plugs with ngk ones.

After a bit of research on the Internet some say that on their m44 engines the consistency of oil has caused issues with their idle on a cold start.

There is however, a tapping, nothing that's too loud, but it can be heard, have a listen:

View: https://youtu.be/qx-biJrw3Ao


Could this be causing anything? Or is that normal.

 

[Zeti]

My engine has , from time to time this tapet noise, especially when idling too long time, but doesn't affect any performance of the engine.

 

[Faheem]

@Zeti that's good then!

I'm thinking of trying the stock NGK spark plugs as a last resort and may try swap out the ccv out with the one in the other z3.

 

[Sean d]

@Zeti that's good then!

I'm thinking of trying the stock NGK spark plugs as a last resort and may try swap out the ccv out with the one in the other z3.

Take the advice mate and do a compression test, it is quite obvious from the engine turning over that something is wrong in that department

 

[Faheem]

@Sean d You are spot on but I'm worried about the results hence why I've been putting it off for such a while. A tester isn't exactly expensive, about a fiver from screwfix, but the results can be life changing

 

[oldcarman]

@Faheem just do it and live with the result!! You're just wasting a lot of precious time by changing parts that aren't going to make a difference in the end. There's the. Chance that while you're doing all this you could do more damage to your engine and make repairs more difficult and expensive. Something could snap off and take out your piston and cylinder walls, bend valves, etc. So get a tester and just do it!! JIM

 

[t-tony]

I have to agree with Jim, if there's something a comp. test will find it needs finding before you do more damage, the way that engine starts can't be good for it.

Tony.

ps. I have a Snap-on tools tester you can borrow if we can get out to you, or you could come over and do it here.

 

[Mint]

...I have a Snap-on tools tester you can borrow...

Great offer Tony, this is what makes this forum so good

 

[Faheem]

@oldcarman Okay Jim! As I said previously you are very motivating

@t-tony thanks. Would absolutely love to come over to you. However, as you know the problem goes away when the engine reaches operating temp and will take a good 7 hours or so to return. Is a compression test on a warm engine any good?