Group, (122-Wagon noise)

Well.... I pulled the timing cover and found a steel crank gear as well as a steel cam gear. I've have since bought a new gear set with a fiber cam gear and new steel crank gear and was going to install it this morning. After pulling the cam nut on the existing steel cam timing gear I noticed a few things that didn't add up to me. It's been a while since I've played garage mechanic but let me run this by the group and tell me if I'm crazy....

Remember, the engine runs great, except for this knock/noise.

The marks on the cam gear and the crank gear line up when the #4 cylinder is ATDC.

If the firing order on this B20B is 1342 with # 1 at the front of the block or closest to the radiator, which I would assume it is, the timing gears line up with their marks w/#4 ATDC.

When I rotate the engine to show that the distributor rotor is firing on #1, and the valves are both closed, the crank gear mark is where it should be but the cam gear mark is 180 degrees away or exactly opposite of where it should be. Additionally, the marking on the distributer housing indicating #1 is lining up when the rotor is pointing to number 3........ I don't get it... how is this engine running?

My simple question is the firing order and location of # 1. Without at manual, one has been ordered, I'm only guessing that # 1 is at the fron of the car. Is it? If it's at the rear, I still have a distributor issue but I can't understand how the engine can be running well with all of these timing issues??? Perhaps the noise is one of the pistons hitting a valve but that wouldn't last long......

Since I first wrote I have learned a few more thing about the car. The engine is a B20B mated to a M40G trans with a J overdrive unit. The OD works in all gears, which is a tad scary because the switch is incorperated in the turnsignal switch which may have either been a high/low flasher or the power window washer pump acuator.

Thanks, Bill

Steel gears are better than fiber gears - so don't change!
Note that #1 and #4 are both at TDC at the same time. The marks on the
gears are for installing the gears, NOT determining TDC. Timing marks are
for that.

You should check the brass plate behind the timing gear. If it is worn that
would give you forward/aft motion of the camshaft and possibly knocking also.

Changing from steel gears to a fiber gear (and you DO have to change both
gears if you do that) is a step backward in reliability and longevity.
Steel gears may be slightly noisier but it is usually not detectable inside
the car.
--
George Downs Bartlesville, Heart of the USA!

George,

Just posted my findings and I didn't get anywhere. I changed the gears with a matched set, albeit a fiber cam gear. Changed the brass plate behind the cam gear as well. Darn noise is still there. I put everything back together but I'm thinking that I should just pull the engine and start from the begining so I know what I have.

Can't tell if it is in the valve train or a rod knock. I would figure that a rod knock would vibrate and run through the full rpm range. This sound goes away at about 1500 2500 rpm.

Tired and disapointed...... I do know more about the car though.

Happy Holidays everyone!

Bill

Have you done things like listening into the oil filler opening, etc,
to try to locate the sound? What is your valve clearance?
--
George Downs Bartlesville, Heart of the USA!

You have a dangerous situation regarding your overdrive. DO NOT back up with the overdrive engaged. The one way clutch in the unit will be destroyed. There is (supposed to be) a switch on the top cover of the transmission that is normally open, and closed when fourth gear is engaged, to permit overdrive only in fourth gear. It sounds like a previous owner bypassed it when wiring it up. This should be corrected as soon as possible. It has nothing to do with what dashboard switch is used. If overdrive is controlled by pulling back on the turn signal switch, that was originally the high/low beam switch for European models. (US cars have a floor mounted switch for this function) If you find this satisfactory you can keep it that way.

The cylinder at the front is number one. It is physically impossible for the valves to hit the pistons on a B18 or B20, even if the teeth shear off of the gear and the cam stops turning (this has happened to me more than once) It sounds like whoever put the present set of gears in didn't get the marks lined up correctly and fiddled the distributor to match.

You mentioned scraping off window tint in your previous thread. Always use a NEW razor blade when doing this (an old one may have nicks in the blade which can cause scratches) and don't hold it at too steep an angle.