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240 240 Weird Engine Shaking Symptom

smeha

smeha

Tranny Whisperer
Joined
Mar 3, 2017
Location
California
Hello everyone,
Car: in sig, 245 with AW70 and B230F
Problem:
- Engine shake every 1-2 seconds (no specific pattern, just as an example 1-2 seconds)
-- Fine for couple seconds and then makes a dive for less than a second.
-- RPM, speed, neutral position doesn't seem to affect it.
- Timing jumps 2-5 degrees randomly with every start of the car.
-- Ex: one time start its 12 degrees, another its 16 and stays until you restart the car.
Background:
- New genuine Volvo engine mounts.
- New sparks, cap, rotor.
- 2 y/o IPD spark wires.
- No vacuum leaks (smoke test).
- Throttle body new gaskets and cleaned.
- MAF cleaned and disconnecting it makes it worse, so seems working fine.
- 4-5 y/o O2 sensor.
- 3 y/o Bosch ignition coil.
- 4 y/o harmonic dumper.
Edit - Just replaced Chrysler box with known working one, cleaned connector and check vacuum. Nothing has changed.

I was suggested by a friend of mine that I might need to replace distributor, if yes any tips and something i need to know?
Any other ideas?

Thank you
 
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Try to raise the spark wires off of the valve cover, it's possible some spark is going through the insulation if it's old/oily enough
 
So what all of you saying if water spraying won't reveal spark problem (voltage leak), it's a box with a vacuum connected to it near wiper water tank?
How i can test that?
Are you sure its not a distributor?
 
Bump, got known used Chrysler box, cleaned connectors. Still the same shaking, haven't checked timing weird thing yet.
 
Oxygen sensor could be slow? It's 4-5 years old. What brand? Check it's voltage on a warm idling motor.

I don't think these cars are notorious for idling all that well anyway. It's a big 4 cylinder with no balance shafts.
 
PromiseRing said:
Okay why would that matter? The o2 sensor isn't only important 'at idle'; it's important at all other rpm ranges too I believe.
Click to expand...

Well thats how it sounded in your post, just saying. I'm not the sharpest tool in the garage and have no idea that o2 can be causing this weird shaking, I always thought it would run rich/lean depends where it stuck.

Oxygen sensor could be slow? It's 4-5 years old. What brand? Check it's voltage on a warm idling motor.

I don't think these cars are notorious for idling all that well anyway. It's a big 4 cylinder with no balance shafts.
Click to expand...

Also, what is the correct procedure and readings for the 240 O2 sensor, 3 wires?
 
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smeha said:
Well thats how it sounded in your post, just saying. I'm not the sharpest tool in the garage and have no idea that o2 can be causing this weird shaking, I always thought it would run rich/lean depends where it stuck.



Also, what is the correct procedure and readings for the 240 O2 sensor, 3 wires?
Click to expand...

Trust me I'm not either:lol: I'm not saying that's your issue for sure, as a LOT of things can cause a stumble idle, but it could be.

Eh there's a writeup on brickboard I think. But it has something to do with getting the car into closed loop (warmed up) then checking voltage at the connector. Should fluctuate between .1-.9v iirc. .5v being stoichimoetric.
 
smeha said:
Hello everyone,
Car: in sig, 245 with AW70 and B230F
Problem:
- Engine shake every 1-2 seconds (no specific pattern, just as an example 1-2 seconds)
-- Fine for couple seconds and then makes a dive for less than a second.
-- RPM, speed, neutral position doesn't seem to affect it.
- Timing jumps 2-5 degrees randomly with every start of the car.
-- Ex: one time start its 12 degrees, another its 16 and stays until you restart the car.
Background:
- New genuine Volvo engine mounts.
- New sparks, cap, rotor.
- 2 y/o IPD spark wires.
- No vacuum leaks (smoke test).
- Throttle body new gaskets and cleaned.
- MAF cleaned and disconnecting it makes it worse, so seems working fine.
- 4-5 y/o O2 sensor.
- 3 y/o Bosch ignition coil.
- 4 y/o harmonic dumper.
Edit - Just replaced Chrysler box with known working one, cleaned connector and check vacuum. Nothing has changed.

I was suggested by a friend of mine that I might need to replace distributor, if yes any tips and something i need to know?
Any other ideas?

Thank you
Click to expand...

You mentioned the "timing jumps 2-5 degrees randomly with every start of car" ? Curious how you are checking timing ? If using marks on harmonic balancer, could it be slipping ?
 
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Requesting a video or something of this shaking. I haven't seen one of these engines that didn't shake occasionally, especially with the OEM jelly mounts that wasn't brand new or freshly built
 
Answer to all, harmonic only 4 years old and when checking with timming, it doesn't jump. It changes with start of the car.
I wrote above, mounts NEW Volvo, 1 is HD diesel and another regular. Both from ipd.
I will to try do the video.
 
Funny, my 88 244 has that EXACT same problem. I haven't been able to figure it out yet. Didn't check the timing because I don't have a timing light, but did check the voltage on the hall-effect sensor, that turned out fine. I repaired a few of those female bullet connectors on the ignition pigtail box by wrapping some copper flashing around the fastener and stuffing back into the plastic housing, with no change. Replaced the ignition coil, wires are new-ish like yours--all of that crap.

It's quite strange to me because I was just giving my room mate hell about how wonderful the car was driving, until he took it for a spin and the radiator burst, sprayed coolant everywhere, while warping the head in the process. The slight backfire I had occasionally became more pronounced and began to misfire and hesitate/ shake across all rpm ranges. Mine probably needs a new engine!

Please keep us posted and let everyone know how and when you solve this frustrating problem.
 
durk80 said:
Funny, my 88 244 has that EXACT same problem. I haven't been able to figure it out yet. Didn't check the timing because I don't have a timing light, but did check the voltage on the hall-effect sensor, that turned out fine. I repaired a few of those female bullet connectors on the ignition pigtail box by wrapping some copper flashing around the fastener and stuffing back into the plastic housing, with no change. Replaced the ignition coil, wires are new-ish like yours--all of that crap.

It's quite strange to me because I was just giving my room mate hell about how wonderful the car was driving, until he took it for a spin and the radiator burst, sprayed coolant everywhere, while warping the head in the process. The slight backfire I had occasionally became more pronounced and began to misfire and hesitate/ shake across all rpm ranges. Mine probably needs a new engine!

Please keep us posted and let everyone know how and when you solve this frustrating problem.
Click to expand...
1988 year lol the same.
I wonder if it could be the ignition and/or maybe engine harnesses? I had a crappy shop few months ago to replace bearing rod main set and oil pan. They could've damage ignition wiring. I should mention, the engine/ignition wiring is all original. Ground points are cleaned and fine, battery terminals replaced/cleaned.
 
Otto Mattik said:
A) Have you checked adjustment bolt on distrbtr make sure it's not loose ?
B) Remove timing cover and verify timing ?
C) Harmonic Balancer is NOS ? (what do you mean by "4 years old" ?)
Click to expand...

A) Tight
B) Last time I checked couple years ago when replaced timing belt and it was perfectly aligned, and the issue came up only few months ago.
C) It was new IPD one bought and replaced 4 years ago. Honestly. how many times i gotta repeat that balancer is fine. When i check timing it doesn't jump or anything, I know how worn old balancer look like, the one i replaced 4 years ago.

Thanks
 
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