Engine time with codes

bear2020

bear2020

Zorg Guru (I)
Supporter
British Zeds
Joined
Dec 13, 2020
Points
98
Location
Norwich
Model of Z
Z3 3.0 & Z4 2.5
The bodywork is nearly finished ( i say that its really only one side!) so time to move onto the engine

I've ordered the following from X8R
disa valve (fitted today) Old one was pretty chewed up
The Vanos full repair kit
And the leaking oil pump gasket

Car always ran lumpy from when I picked it up but just plugged a C110 on it and got these codes. Cleared the codes and ran it for 5 mins and all came back

E4 Fuel trim bank 2, permissible range exceeded
E3 Fuel trim bank 1, permissible range exceeded
CA Fuel trim bank 1 control limit
CB Fuel trim bank 2 control limit
EE Misfire cylinder 1
F2 Misfire cylinder 5
F0 Misfire cylinder 3
F3 Misfire cylinder 6
EF Misfire cylinder 2
F1 Misfire cylinder 4

Anyone point me in the right direction as car has rapidly become a money pit!
Z3 2000 3.0
Cheers
 
Just noticed my Air Intake has a dirty great big split on the underside which may be a cause of some of those codes I would assume! New one now ordered...think these older BMW's stand for Blimey More Wad!
 
The induction hose being split would most likely have been the root cause of most of your problems. Check the other one as it will most likely be the same age. Very reasonable price for after market ones on eBay and Amazon.

Tony.
 
t-tony said:
The induction hose being split would most likely have been the root cause of most of your problems. Check the other one as it will most likely be the same age. Very reasonable price for after market ones on eBay and Amazon.

Tony.
Click to expand...
Cheers Tony Think I will order both and replace them at the same time and be done with it
 
All miss fires are induction hose split check ma's sensor Bank 1 Bank 2 check fuel trim and lambda sensors
Bank one is cylinders 123 and Bank 2 are 456 cylinders the reason I say check fuel trim is your code reader says its been exceeded
 
Robert Hill said:
All miss fires are induction hose split check ma's sensor Bank 1 Bank 2 check fuel trim and lambda sensors
Bank one is cylinders 123 and Bank 2 are 456 cylinders the reason I say check fuel trim is your code reader says its been exceeded
Click to expand...

It's been exceeded because of the unmetered air drawn in through the split intake boot.

Tony.
 
The induction hose split may be one of several vacuum leaks. These cars are getting old and lots of the rubber parts are splitting.

Fit your new induction hoses and go for a good drive. See if all the codes are gone. Then look at the fuel trims. When the car is all sealed up with no vacuum leaks, the Long Term Fuel trims should be within the range of +/- 4%.

This Vacuum leak test is helpful in seeing if you have any vacuum leaks left.

The proportion of unmetered air from a vacuum leak to metered air is higher at idle and lower at revs. Do this test.

With a hot engine at idle, check the 4 fuel trims, 2 short-term and 2 long-term. If any are > 8% then you likely have a vacuum leak. Rev the engine to 3,000 rpm for 30 seconds and watch the short-term fuel trims. If they reduce significantly, might even go negative, then it is confirmed that you have a vacuum leak. Smoke test the engine to find the leaks.

If the short-term fuel trims do not reduce significantly, then it’s something else.
 
Just to conclude this replaced both parts of the hose to and from the MFA and all codes cleared up and the car actually ticks over - first time I have heard that since I've owned it. Nice to finally hear all 6 cylinders firing away merrily. Then the expansion pipe decided to crumble and fall apart throwing up other codes LOL Old cars are like old houses fix one thing and 20 other things fall apart!
 
Resurrecting this thread as I have a similar issue on my 2.2.

The trouble is that its never consistent. Sometimes the EML lights up and - for instance, this morning - I get the codes…


CA fuel trim bank 1 control limit
CB fuel trim bank 2 control limit
E4 Fuel trim bank 1, permissible range exceeded
E4 Fuel trim bank 2, permissible range exceeded
EE Misfire, cylinder 1

…then sometimes the car is fine for a month or so. Would a vacuum leak work this intermittent way? Surely it would be on all the time.

I’ve changed the MAF to a new Delphi one and still have the issue. Once cleared with a C110 its fine again for a few weeks, then will reappear. Whats also confusing is the car when showing as misfire, is misfiring, but when you clear the code its stops misfiring Which would lead towards a sensor issue right?

One thing I noticed when looking at the values for the O2 sensors was that on tickover, both sensors before the cat. fluctuate between a low number (e.g. 0.11) and a higher one (e.g. 0.78), whereas the after cat. sensors seem to stay stable at the higher number, e.g. 0.76.

I’ve looked for vaccum leaks in the hoses too but havent been able to see any splits.

Any other ideas?
 
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Probably the quickest check would be to start it, let the idle simmer down, lift the hood and spray some brake cleaner around the intake piping and various vacuum lines/caps. If the idle jumps, you got a leak. Try not to get the exhaust, for obvious reasons. 🔥
 
Your O2 sensors are giving correct values.

At hot idle, look at your fuel trims, there are 4 of them. 2 Short Term fuel trims (STFT) and 2 long term fuel trims (LTFT). If any are >10% then you likely have a vacuum leak.

List the 4 fuel trims here
 
Thanks gents. I’ll take a look and appreciate the help 👍🏼
 
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