Misfiring Engine Thanks - The Unofficial BMW M5 Messageboard (m5board.com)

Brian M5 · 18th September 2003, 00:46

Had to start a thread to pass on my gratitude for such a great forum. Just stopped a severe panic attack.
I have just made it home with what I thought was a very sick engine. Only firing on 4 cylinders. I feared the worst given past experience (£££££) . As soon as I could, I searched through past posts and found the solution I hoped for (an easy one).
The misfire was caused by water ingress to the front plug recesses. What a design coup that is. No more engine cleaning for me, my guess is, you can't even lift the bonnet when it is raining!!!
Thing is the car had run for days since I cleaned the cam cover. Once the problem arose the engine ran perfectly when cold but as soon as it reached operating temperatures the misfiring started. On investigation, I couldnt believe it was firing at all given the volume of water that was in the recess. The front plug was under water. Have to say also that it took 3 repeats of removing and drying the coil packs and plugs before the misfiring stopped.
To the uninitiated you would think the heat from the engine would soon evaporate any excess water. Think again!!!

BTW took some pics of the repair - how do you attach them to a post.

Thanks
Brian

ECM4 · 25th September 2003, 15:10

Brian,

Could you imagine how much more difficult it would be to run one of these cars without access to so much information and technical knowhow. There's a lot of people on this forum with lots of knowledge and experience. The site will contribute greatly to sustaining these cars existance in the longer term.

Yes, maybe someone could explain the 'photo' problem to me too!!!

PS: Have you solved the front suspension problem yet?

Brian M5 · 29th September 2003, 01:34

Yes there is stacks of good information here.

The front suspension links and bushes have been changed on both sides now. No change to the handling though and as time passes it has become easier to diagnose the problem to the shock absorbers. The nearside front unit is now visibly damp so I now have the replacements bought (10% discount at Dunedin).

Should all be fitted up in the coming week.

IvanDias · 29th September 2003, 02:05

Quote:

Originally posted by Brian M5
BTW took some pics of the repair - how do you attach them to a post.

To link a picture and display it on a post.

1. You need to get the picture onto a website, either FTP it up onto a domain that you own, ie. a website that you have made, then link to it, otherwise you can upload them to bmwm5.com.
Details here

2. Once the picture is somewhere on the internet, then to add it into your post is easy. Just click the IMG button when writing your post, then type the full address of your picture into the box that appears. Remember the http://www bit of the address.

An easy way to find the address is to use Internet Explorer to find and display your picture, either on the bmwm5 dot com gallery or uploaded to your website. Click on the picture with the right mouse button, and select "properties" from the menu that appears.

You will notice on the grey details box that appears, that the full url (address) or the picture is listed. You may either write this down and then type it into the IMG box as above once you are ready.

To be extra clever, use the mouse to select the text of the pictures address then right mouse and copy. Go to the IMG box dialogue and then right mouse and paste the url in there.

If you prefer, then you can manually enter a picture address. Whilst typing your post, type in something like;

[IMAGE]http://ww.abcwarrior.com/GFX/bmwroundel.GIF[IMAGE]

Only don`t put the word IMAGE, put the three letters IMG, and put three "w"s after the http:// address.

I can`t enter it correctly here as obviously it would display the picture instead of showing you how to do it.

Hope this helps.

Ivan

Brian M5 · 3rd October 2003, 21:19

Thanks Ivan

I'll try it out

Water gets in at the side of the Oil Filler and gets trapped in the readily built dam area at the front plug. If more water gets in it overflows each weir in turn affecting more plugs / cylinders.

In my case the front plug was under water and had to be syphoned off and dried with rags poked in on a long screwdriver (whilst holding onto the end of the rag obviously).
Plug 2 was also wet and got the rag treatment.
The rubber connector does a good job of sealing the water in but is less effective at sealing it out. I believe it is actually a non return valve for the unwary.

Then remove the plugs, dry out, replace and repeat as necessary. 3 times in my case.
The misfiring cylinders could be identified from a visual inspection of the plugs.

Information on the misfire was gleaned from previous helpful posts.

M5touring reg · 3rd October 2003, 22:56

that's strange bcs although this is a common problem and you shud never use high-pressure-cleaner on your engine-bay,
normally cylinder 1 + 2 nearest to the windscreen get effected,
simply bcs they are at lowest level, cylinder 5+6 at highest
level being effect is news to me, but -hey- we learn from each other every day - INTERESTING ! THKS FOR THE PICTURES, WELL DONE job!

Brian M5 · 4th October 2003, 10:36

Yes Karl

I had been attempting to clean the engine and had carefully rinsed some gunk off the cover a couple of days earlier with a watering can of water. I had not come across this problem before although I had a 1990 M5 for 5 years and it's engine was clean!!That is where the problem started.

Notice the bubbly yellow sealer that is on the engine. Looks like it has been there since new maybe and has the appearance of old varnish.

Anyone got any good ideas for its removal cos it dont look pretty.

mikek · 4th October 2003, 12:17

My M5 had that stuff all over the "BMW M POWER" enblem on the rocker cover (3.6). It is actually a protective coating sprayed onto the engine at first manufacture. I removed it using ordinary wire wool (plumbers shop) and a vacuum cleaner to catch the bits. It worked a treat! End result was a shiny emblem!