Constant wet plugs so can' t start M54 engine.

[Bluebottle]

Hello there, my E89 is going well so I decided to do a bit of work to my E39 525i. It burns oil (4litres /1000miles!), probably from seized oil rings but nevertheless starts and goes really well, no issues accelerating to red line. The plugs are constantly black and fouled, so I replace them with clean ones every 1000 miles. Last week I decided to remove plugs and squirt Redex in combustion chambers, replace plugs and leave that to soak, hoping it would loosen the rings.
I have now gone through the following cycle three times leaving the plugs out overnight for evaporation and recharging battery, and another three times today. The engine turns over quickly as usual but apart from a few weak attempts to start initially it just rotates without any ignition at all. No error codes at all (except when the fuel pump fuse is removed). I have accelerator to floor WOT and then without any pedal but no difference.

Fit plugs, turn engine over ten 5second bursts
Remove wet fuel soaked plugs and fuel pump fuse, turn engine over ten 5second bursts
Refit clean dry plugs, no fuel, ten 5second bursts
Refit fuel pump fuse, ten 5second bursts
Even brand new NGK plugs refused to start, they came out dripping with fuel!
I will leave for another week with plugs out, but am confused and very concerned about the state of my Catalytic convertors.
Any advice gratefully received.

 

[enuff_zed]

If the rings were seized then possibly the only thing maintaining compression was the carbon build up on the bores.
I'd be concerned that the Redex has cleaned off the deposits and left you with no compression at all.
I think you need a compression check.

 

[Bluebottle]

Thanks, that had crossed my mind
I shall try and borrow the tool off a friend. Last time I used it the readings were around 200.

 

[Bluebottle]

Compression check done.
No 2, 150 psi
All others, 60psi dry, 120psi with a little engine oil in chamber. :thumbsdown:
Will try to dry chambers out of fuel/ Redex and oil with tissues and refit plugs for another attempt next weekend. :headbang:

 

[enuff_zed]

Compression check done.
No 2, 150 psi
All others, 60psi dry, 120psi with a little engine oil in chamber. :thumbsdown:
Will try to dry chambers out of fuel/ Redex and oil with tissues and refit plugs for another attempt next weekend. :headbang:

Bu**er!
I have a feeling the damage is done tbh.

 

[Bluebottle]

Oops

 

[Bluebottle]

Compression check done.
No 2, 150 psi
All others, 60psi dry, 120psi with a little engine oil in chamber. :thumbsdown:
Will try to dry chambers out of fuel/ Redex and oil with tissues and refit plugs for another attempt next weekend. :headbang:

Bu**er!
I have a feeling the damage is done tbh.

I know you do.
I hope to prove you wrong :wink: :wink:

 

[enuff_zed]

Compression check done.
No 2, 150 psi
All others, 60psi dry, 120psi with a little engine oil in chamber. :thumbsdown:
Will try to dry chambers out of fuel/ Redex and oil with tissues and refit plugs for another attempt next weekend. :headbang:

Bu**er!
I have a feeling the damage is done tbh.

I know you do.
I hope to prove you wrong :wink: :wink:

Got my fingers crossed!

 

[Mike6]

Looks like the cylinder head needs to come off for a closer inspection or perhaps a camera into the bore.

 

[Bluebottle]

Thanks Mike6. :wink:

 

[Mike6]

Rereading your original message, you dont say what mileage is on the car. They are very robust engines so unless car has been thrashed over high mileages or skimped on maintenance you are very unluky. What makes you think it is seized oil control rings other than say worn valve stems, worn cylinder bore or simply worn piston rings.
I have not had to remove a cylinder head on a Z4 but have done plenty of other engines. Is car your daily drive, if not take it a step at a time , it is after all just nuts and bolts but I am sorry in saying that cylinder head has to come off for a proper inspection. Where do you live, maybe other owners could come and help.

 

[Bluebottle]

Hello Mike6, thank you for encouraging me.
To answer your questions.
Mileage is 122k (in the signature :wink, bought in 2013 with 77k and driven very carefully by me since, ie. allow engine to warm before exceeding 3000rpm and then driven as a BMW should be. It has always consumed oils since I bought it, but has gradually worsened, with constant subtle misfire. ( I thought the vibration was clutch and DMF so had that changed in 2017.
Oil replaced with quality Fuchs LL01 and filter annually. CCV and related pipes replaced 2014, various tests done to 90% exclude EGR system. Apparently valve guides send out blue oil smoke on over-run, something my car has never done; it occasionally sends blue smoke out on start up, especially when warm.
I foolishly thought a total of half a bottle of Redex in the cylinders would loosen the stuck oil rings, but obviously not!

By the way, this is my E39 525i, not my Z4, it has been regularly used as daily since 2013, usually 7 miles to work and then back, with occasional longer trips.
I will retry the start up carefully again the weekend. If no luck then will seek further advice /help.

I am in Plymouth.
Cheers.

 

[Motionblurrr]

I had a headgasket scare during the summer because my car developed a misfire and I chased my tail finding out what it was.

Did you do the compression test yourself? This is going to sound kind of dumb like if I think I don't know what you're doing (because it happened to me). If you did the compression test yourself, did you take out all of the sparkplugs before you did the compression test? If you leave a few in the readings are definitely not accurate.

Good luck, I hope it's not the head. It's my worst fear tbh because I have about 174K miles on my car and I try to baby it

 

[Bluebottle]

Well, here goes.

More compression tests, drying wet plugs and cranking engine.

With a little oil in chambers.
No 1. 100psi
No 2. 280
No 3. 60
No 4. 70
No 5. 60
No 6. 230

After repeated cranking, a few attempts to ignite fuel but ultimately engine will not run. I can confirm sparks from No 1 and 2, I didn't bother checking others as I don't doubt the others.

Compression after all this:
No 1. 70psi
No 2. 195psi
Then I gave up concluding, there is good compression on No 2 and 6, other four hopeless!

I spoke to BMW indy and he may be able to get a new engine from BMW and quoted £3000 - £3500. That sounds like a bargain for a new engine, but as always, I welcome your opinions.

 

[bigwinn]

I think that’s bloody expensive for a used m54

£1k max for a mid miles engine I’d say plus fitting et al

 

[enuff_zed]

I think that’s bloody expensive for a used m54

£1k max for a mid miles engine I’d say plus fitting et al

I agree. Given that they are usually good for 250-300k, I would be looking for a good secondhand one, even if it has 100k on it. If you can get a complete one then you have a few ancilliary parts you could sell on to recoup a bit.
I believe Mr [ref]bigwinn[/ref] has experience at swapping these engines?
Pretty sure he would be both cheaper and more conscientious.

 

[Bluebottle]

I think that’s bloody expensive for a used m54

£1k max for a mid miles engine I’d say plus fitting et al

No, you misunderstood me, he said for a new engine direct from BMW. :wink:

Please tell me how I can get hold of a "good" second hand engine, something with a guarantee so I don't waste time and money fitting it. Please appreciate that my E39 is my perfect car, not something to last another couple of years, but until I can no longer drive or the government outlaws it.

 

[Motionblurrr]

Was that car overheated at one point?

 

[Bluebottle]

Was that car overheated at one point?

Never by me

 

[bigwinn]

I think that’s bloody expensive for a used m54

£1k max for a mid miles engine I’d say plus fitting et al

No, you misunderstood me, he said for a new engine direct from BMW. :wink:

Please tell me how I can get hold of a "good" second hand engine, something with a guarantee so I don't waste time and money fitting it. Please appreciate that my E39 is my perfect car, not something to last another couple of years, but until I can no longer drive or the government outlaws it.

Understood

If your e39 is that cherished then gambling on a used m54 with 100k+ miles may not be to your tastes… although despite the issues yours has I’m of the opinion that they are good, strong engines if looked after

Otherwise I’d be looking to the usual trusted breakers for a 3.0 e39, e46 or even z4 for an engine with service history

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