E34 M50 Tick Tick Tick Tick Tick... Help!

[wishihad50k]

I know that this problem is nearly impossible to diagnose by reading a post but I thought I'd give it a shot anyway. My engine has a nasty Tick Tick Tick at idle. It only happens once and a while and its not very consistent (it happens when its cold, hot, right after start up, etc.). If I give it a little gas and rev the engine it goes away for a bit and comes back. I tryed to clean the fuel injection with a can of BG44 K and that stopped it for about a month, but then it came back. I have also noticed lately that is smells like gas in the cab??? I need some help! I thought maybe exhaust leak? Any suggestions would be great! Thanks guys!

[shogun]

Which M50 engine do you have?
The BMW M50 is an I6 piston engine. It was introduced in 1989 to replace the BMW M20 and was replaced by the BMW M52 in 1994. Displacement ranges from 2.0 L to 3.0 L. It is a DOHC 24-valve engine. A Technical Update or M50TU version from 1992 introduced VANOS variable valve timing.

The M50 was related to the M20 with the same 91 mm cylinder spacing, bore, and stroke at 2.0 and 2.5 liters.

M50B20
The 2.0 L (1991 cc) M50B20 was introduced with the 1989 520i. It has an 80 mm bore and 66 mm stroke and produces 150 hp.

Applications:

1989 520i
M50B25
The 2.5 L (2494 cc) M50B25 was introduced with the 1992 525i. It has an 84 mm bore and 75 mm stroke and produces 192 hp.

Applications:

1992-1994 525i
Note: This is the engine from which the M50TU evolved. The VaNoS update was added late 1992 and sold for 1993 model year E34s.

M50B30
The M50B30 was a 3.0 L version, which powered the US-spec E36 M3.

VANOS (Variable Nockenwellen Steuerung) is an automobile variable valve timing technology developed by BMW. VANOS varies the duration and lift of the intake valves by moving the fulcrum of the camshaft. BMW recently began offering "double" VANOS, which operates on the exhaust camshaft as well, on the BMW 3-series cars.

(copied from a BMW info page)

[Rory]

I know that this problem is nearly impossible to diagnose by reading a post but I thought I'd give it a shot anyway. My engine has a nasty Tick Tick Tick at idle. It only happens once and a while and its not very consistent (it happens when its cold, hot, right after start up, etc.). If I give it a little gas and rev the engine it goes away for a bit and comes back. I tryed to clean the fuel injection with a can of BG44 K and that stopped it for about a month, but then it came back. I have also noticed lately that is smells like gas in the cab??? I need some help! I thought maybe exhaust leak? Any suggestions would be great! Thanks guys!

Sticky lifters.....let me guess that it goes away above 2500 RPM's or so? It is perfectly acceptable but annoying. Many (including myself) have suffered from this on the M50 and it is the price yout wy for not having to do valve adjustments. What weight oil are you running? Synthetic or dino? I was running 20W-50 and the tick was really bad. Switching to 10W30 (Mobil 1 on both) takes care of most of my problem. Also, a long jaunt down the highway in 2nd and 3rd gear (5-nearly 7K RPM's) helped my noise out a lot. I think I had/have a lot of carbon buildup on the valves due to lots of short trips so the valves tend to stick a bit causing the noise. I would play with oil weights and drive it like you stole it for a few days and see if it helps.

Good Luck,
Rory

[6670charger]

I know this is a bit out of order in the scheme of replies at the top. I've been doing just as suggested by driving the car like I stole it after having changed to 10W-30 part synthetic oil and adding Liqui-Moly lifter cleaner. When I drive the car on the Autobahn for about 7-8 miles at 110mph or so, the engine seems to quiet down at all speeds for about 3 days, but then the lifter clatter starts up again during city driving. Only happens when the engine is warmed up to normal temp. When it's cold, it sounds normal.

I'm taking Bill's suggestion and changing out the gasket for the oil pickup tube in the oil pan tonight to see if the problem might be air getting into the oil causing foaming at warmer temps. I'll post and let everyone know if that solves the problem. If that doesn't solve the problem, I'm open to suggestions.

[Russell]

I know this is a bit out of order in the scheme of replies at the top. I've been doing just as suggested by driving the car like I stole it after having changed to 10W-30 part synthetic oil and adding Liqui-Moly lifter cleaner. When I drive the car on the Autobahn for about 7-8 miles at 110mph or so, the engine seems to quiet down at all speeds for about 3 days, but then the lifter clatter starts up again during city driving. Only happens when the engine is warmed up to normal temp. When it's cold, it sounds normal.

I'm taking Bill's suggestion and changing out the gasket for the oil pickup tube in the oil pan tonight to see if the problem might be air getting into the oil causing foaming at warmer temps. I'll post and let everyone know if that solves the problem. If that doesn't solve the problem, I'm open to suggestions.

I have the warm idle lifter noise, only after the oil has about 3,500 miles on it. Looking forward to your results. I would think that changing the oil pan gasket is a bit of a pain on the M50.

[6670charger]

Yes, it was. I spent about 8 hours working on the thing the other day. The gasket behind the oil pickup was the culprit. Lifters are nice and quiet now.

Had to lift the engine a couple of inches to create some clearance to get the pan out, and then remove the driver-side motor mount to replace two of the pan bolts.

[Russell]

Thanks, Looks like it will only be done by my Indy in my case. I hate the thought of his labor cost.

[6670charger]

The only thing that saved my butt was that I'm on a military installation, and we have what's called an Auto Craft shop. It's a fully stocked garage with workbays, lifts, tools and a few coaches who help out or give you pointers on what needs to be done. You do the lion's share of the work yourself. Costs me $7/hr for a lift bay, so I spent $50. Total was about $75 with the parts.

If it hadn't been for that, I'll bet it would have cost me a good 150-200 euro (around $200-300) to get it done provided any local mechanic would even look at a car this old. Might have had to take it to BMW, or else just junk it.

[Burell]

I know that this problem is nearly impossible to diagnose by reading a post but I thought I'd give it a shot anyway. My engine has a nasty Tick Tick Tick at idle. It only happens once and a while and its not very consistent (it happens when its cold, hot, right after start up, etc.). If I give it a little gas and rev the engine it goes away for a bit and comes back. I tryed to clean the fuel injection with a can of BG44 K and that stopped it for about a month, but then it came back. I have also noticed lately that is smells like gas in the cab??? I need some help! I thought maybe exhaust leak? Any suggestions would be great! Thanks guys!

The funny thing is ... I had what I thought was a ticking valve/sticky lifter too. After I replaced most parts of the cooling system (the famous exploding plastic impeller) the tick has totally gone since. These would still be unrelated events in my book hadn't had my father _exactly_ the same thing (familiar tick->failing waterpump) with a totally different car (GM).

Explanations anyone?

Burell

[wishihad50k]

I will try to use different oil weights, and "drive is like I stole it" (dont need an excuse to do that). If it was sticky lifters, would it come and go though? It doesnt do it all the time (thank you God) its very random, but its always during idel and yes it goes away after 2500 rpms. Thanks for the suggestions!