Engine Noises at 3000-4000 RPM when cold

0

Question:

My 73tii has recently developed a noise that sounds like something vibrating, and happens between 3000 and 4000 rpm’s when cold. From the driver’s seat, the sounds seems to come from just beyond the firewall, and down around the transmission. Once warmed up, the noise goes away. Any ideas on what this might be? As far as I know the engine has not been rebuilt, and is probably pretty tired. Timing chain noise? Piston slap?

Thanks, Dave

Answer:

We have some recommendations, but we can’t be for sure on this one. If you have access to a lift, you may be able to pinpoint it yourself. An experienced BMW mechanic could probably pinpoint it with a stethescope on a lift.

Noises in the region you are speaking of could be:

  • Your transmission throw out bearing could be making the noise, try holding the clutch in, does it go away?
  • How old is the starter? The starter pinion clutch may be worn out and slipping out onto the flywheel gears and making contact at high RPM. This happened to me before and it was an awful vibrating racket near the firewall, and could be heard easily.

Back to your original comments:

  • The timing chain is at the front of the engine, not the rear. The timing chain noise is more of a “grrrrrrr”, and can be adjusted. See our other how to on that one:

Noisy Timing Chain: How to bleed your M10

  • The oil pump’s chain is up front also, they usually don’t make noise, they just quietly go bad.
  • In general, wrist pin noise is more of a ratcheting sound and not a vibration and does not go away when warmed up.

Last update: 2009-06-24 19:02
Author: tiiregister

How To Start a Flooded Tii

1

This may be obvious, but It took me 10 years to figure it out. Occasionally my tii will not start the first time when hot. This is usually because of inattention on my part. Some of these times, the engine will become flooded. Because of the design of its fuel delivery system, the tii will not respond, when flooded, to the classical “fix” of putting the accelerator to the floor to air out the cylinders. The only real “fix” is to wait 1-2 hours.

One time in this situation, I removed the fuse controlling the electric fuel pump, thus depriving the engine of added fuel both from the injectors, but more importantly, from the cold start valve the engine then turned over briefly after starting it with the accelerator on the floor. I stopped the engine immediately, replaced the fuse, and drove on.

contributed by: Thomas A. Butterworth

Last update: 2006-12-07 00:11

2002tii Replacement Battery

1

My “new” 1973 2002tii needs a new battery. Any suggestions for a good, maintenance free battery? I remember the “Varta” brand as the OEM battery when I had my original 2002 as well as a few later BMW’s but I don’t think that Varta is sold in the US anymore. Anyone have a battery that could suggest?

Jim Gerock writes: When I bought my 73tii, the previous owner had installed an Interstate brand MT-42 60 Month battery. It’s a tight fit, but it works. Keith Kreeger writes: The original VARTA type battery is still available from any BMW dealer. The  BMW part number is 61 21 1 362 314, which is a 55 amp hour battery according to the most recent parts CD we have. Last update: 2007-06-10 19:27 Author: Jim Gerock, Keith Kreeger

2002tii Alternator Testing Tips

3

After removing my alternator for bushing replacement, I took it to (2) places before I was able to have it tested. The newest computerized charging system tester stations do not list this car in their database. Some places don’t have the correct connector. I first took my original 73 unit to a local Pep Boys service center. They had a fancy new machine that didn’t have the older BMW’s listed. The second place was an Advanced Auto Parts store.

They had a slightly older tester that was used on my alternator – but they claimed the output was too low under load. I neglected to ask “how bad is it”. They also tried to sell me the standard top mount non-tii remanufactured unit!. I finally ended up in a very old Auto/Marine Electric shop very close to my workplace. They tested the alternator and said it worked fine but the bearings were going bad. I decided to order a Bosch AL-40X (still on backorder). After waiting 4 weeks! – my new alternator arrived. It even came with a new black pulley/fan and resistor! Notes regarding the red urethane bushings sold by several companies: They are too thick and the stock washer will not fit under the circlip. Trim the leading edges before installing them. Last update: 2009-06-24 19:01 Author: Jim Gerock

Removing a Tii alternator

1

Easy removal of the Tii alternator

When removing the tii alternator from the bottom, disconnect the sway bar end links and remove the (4) hold down bolts to move the bar forward enough to allow the alternator (with pulley) to drop out of the engine compartment. Also, if you remove the (4) bolts that hold the radiator to the bulkhead – then shift it over about 1″ toward the passenger side, the long pivot bolt can be removed from the upper alternator mount (without draining the coolant!). I must admit, replacing the v-belt is tough; it is VERY tight between the fan and radiator.

Last update: 2007-04-13 18:52

Author: Jim Gerock