Engine Vibration

[Wolfman]

Ok I have been chasing down vibration issues on my Challenger. I have re balanced the rear wheels and had the prop shaft re built and balanced. I also fitted a new gearbox mount, as this looked suspect too. All to no avail. At over sixty the whole car vibrates and then I realised it does it with just the engine running if you rev it up or hold to throttle over a couple of thousand revs. It can be felt through the whole car even through the seat and dash frame. It is generally unpleasant. I did some googling on this and have checked engine mounts and the exhaust is not banging anywhere. I have checked for missing, changed the plugs, resistance checked the leads and used a timing light to check for missing on all plugs as you rev it up. I also took off the fan belts too to be sure but it is still there. I wanted to see if anyone has any ideas. I have taken a step back to think on this and the only thing I can think of is maybe main bearings but it has great oil pressure. If any one is nearby they are welcome to come round and see and have a cuppa too

[mopar_mark]

You seems to have checked & verified a lot of the main causes, one thing I can think of & assuming it’s auto is the flex plate, possible cracked, broken.

[Pete]

I think Mark may be on to something there... it may also be worth checking the Harmonic Ballancer too!

[Wolfman]

You seems to have checked & verified a lot of the main causes, one thing I can think of & assuming it’s auto is the flex plate, possible cracked, broken.

I have turned over the engine by hand and looked at the flex plate and cannot see cracks, Also I have had a crossflow ford with a cracked flex and it made a hell of a Din when running

I do till have to check the harmonic balancer It looks ok, but I will run the engine and see if the timing marks have moved Keep the suggestions coming I don't really want to start stripping the engine for now. I need to get all the rear end sheet metal done and a respray first, I would have liked to sort this before though to get it off my mind.

[Stu]

Am I right in saying you got hit by someone recently? If so, shouldn’t this all be being taken care of by the insurance company?

Ignore me if that’s wrong.

Whatever the case, hope you get sorted soon. Balancer would have been my suggestion after the list you’ve already knocked off, but there are much more knowledgeable people than me on here to help, not least the two above. Good luck!

[Wolfman]

Am I right in saying you got hit by someone recently? If so, shouldn’t this all be being taken care of by the insurance company?

Ignore me if that’s wrong.

Yes it has been since the accident but I have to find the problem first.
It's been 5 months and I am fighting useless solicitors supplied by Brentacre. Every time I phone it's like telling the story over every time as always a different voice on the end of the phone. They tried to submit the claim the other day( to Admiral who are not good to claim from) without the Parts Invoices in the paperwork that I have bought and shipped So I have had to correct them multiple times, then after 5 months they decided a different department had to take over here we go again

[Stu]

That sounds like a nightmare, sorry to hear that.

How come you are having to source the parts yourself? Never had to claim on a classic, thankfully, but when I’ve been taken out by someone in my daily, it’s off to an approved insurance place and the insurance peoples problem.

[Wolfman]

That sounds like a nightmare, sorry to hear that.

How come you are having to source the parts yourself? Never had to claim on a classic, thankfully, but when I’ve been taken out by someone in my daily, it’s off to an approved insurance place and the insurance peoples problem.

I am trying to sort it so JC's do It as I like the way he works and I am having the whole car sprayed at the same time, and I have known him a long time.

[Stu]

That’d be a winner!

[MattH]

Id be tempted to suggest flex plate, a whack on the back wheel could transmit through.
My cracked 318 flex plate sounded like a big end bearing, I even dropped the sump and checked them all before finding a crack in the flex plate.
The flex plates on 318s are very feeble, its a little spider of metal.
I replaced mine with a stronger race type one from hauser's. SFI I think?

[Wolfman]

Ok, it's been a while since I updated this. I haven't had the inclination with all the Bananarama! with the insurance. So I wanted to check the harmonic balancer to check it has not moved (long shot I know) It has been a while since I have had to turn the engine by hand to find the timing marks and I am a bit shocked how tight it is to turn . Once I re-marked them I started her up, no problem. The vibration is still there and seems to be getting worse at various engine speeds. I have checked the harmonic balancer and all timing marks are as it was the last time I checked, a long time ago, so its not that. When I switched off I left it a while whilst I looked at it for divine inspiration to hit me. When I try to turn it over by hand I think it is very tight, Does anyone have any idea's please? I need to find a fellow member nearby to come over and give me their opinion too As until it is repaired I cannot drive it either

[Dave999]

Tight engine that wasn't tight before? but the car was T-boned or rear ended??

a motor with 2 cylinders down vibrates horribly.... unlilkley to do with impact but worth checking, its not nice with one not firing but a couple not firing act as a dead weight in the cycle and will have it rocking about and rattling your teeth

does it run on all cylinders at idle?

something rubbing
something bent
collapsed lifters, valves not opening on 1 or more cylinders (certainly make it very stiff if not impossble to turn over by hand as you force all the compression through the rings)

or it hasn't run for so long everything is dry and you have some minor stiction of rings and bore due to oil or corrosion

plugs out
can you turn it over easier by hand? if so i'd look to the top end/valve train
if not i'd be thinking about converter flex plate just based on the fact that the car took a hit

compression test might show up something.

can more or less garantee it will be the simplest thing rather than the complex thing something daft like drity plug ceramic acting as a short or a couple of ignition leads breaking down.

can you run it off a petrol can of new petrol? just to exclude a bucket load of water addled ethanol fuel in your tank, i presume its done a lot of standing about since the incident.

[Wolfman]

Tight engine that wasn't tight before? but the car was T-boned or rear ended??

a motor with 2 cylinders down vibrates horribly.... unlilkley to do with impact but worth checking, its not nice with one not firing but a couple not firing act as a dead weight in the cycle and will have it rocking about and rattling your teeth

does it run on all cylinders at idle?

something rubbing
something bent
collapsed lifters, valves not opening on 1 or more cylinders (certainly make it very stiff if not impossble to turn over by hand as you force all the compression through the rings)

or it hasn't run for so long everything is dry and you have some minor stiction of rings and bore due to oil or corrosion

plugs out
can you turn it over easier by hand? if so i'd look to the top end/valve train
if not i'd be thinking about converter flex plate just based on the fact that the car took a hit

compression test might show up something.

can more or less garantee it will be the simplest thing rather than the complex thing something daft like drity plug ceramic acting as a short or a couple of ignition leads breaking down.

can you run it off a petrol can of new petrol? just to exclude a bucket load of water addled ethanol fuel in your tank, i presume its done a lot of standing about since the incident.

Hi Dave thanks for your input. It has all new plugs, leads and I am buying a new coil to it's old. Yep seems to be on all cylinders timing light is even too on all cylinders. petrol is super with fuel saver but not that old anyway as I do keep it run up and drive it up and down our private road too. I have taken the plugs out this afternoon and I feel it is still a little stiff to turn over and seems a bit tighter in one spot(I marked the pulley and went though 360degrees) but I don't have another engine to compare to. Maybe I need to remove the flex plate bolts and try it again when time allows.

[Wolfman]

OK, so I had a bit more time on this. I had a mechanic friend come round on Thursday, on the premise of turning over the engine so I could remove flex plate bolts. I wanted him to try turning it, without me having told him what I thought about it being tight. The first thing he said is "christ this engine is tight", so after him confirming my suspicions we put the plugs back in and ran the engine up. For some reason there was a very noisy lifter and number one cylinder that took a very long time to quieten down (its not done that before). After that I left it till today.

So I have taken out flex plate bolts and given the plate a good looking at too. The engine is still very tight to turn (with the plugs out) so not gearbox then? I replaced the bolts and warmed it up, to then do a compression test.
1 =132 psi
2 =130
3 =126
4 =140
5 =140
6 =135
7 =132
8 =132
So not to far apart?
I also did a laser temp check too On the plug it was
1=230F on plug 265 on exhaust manifold
2=209...........315
3=170...........250
4=200 ..........246
5=200...........210
6=240 ..........325
7=168.......... 230
8=190 ..........305

The vibration is most noticeable at about 1800 revs, and it is a bit fluffy as in subtle missing too. I don't know what to do next! any idea's??
I have noticed the left mixture screw does not make much difference to the tick over if screwed right in, but does get unhappy if wound right out thou. The only thing I have not changed is the ignition module now.

[Dave999]

well mine ran horribly last year after a run up to santa pod i spent most of saturday doing what you are doing and in my case the brand new ignition module fitted the day before had the exact same fault as the one i had removed, after limping into Olney car park on 3 cyilders
horrendous journey...




only module no.3 cured the issue
carbs to bits
plugs swapped
rocker tin off to check all was well
dizzy and coil swapped
Gasket leaks loooked for with WD40
swearing and cups of tea...

and it was the bloody module, brand new out of the box broken...

so never say never....
i guess if it wasn't vibrateing you'd never know it was stiff...maybe its always been stiff.. is that a red herring....?

if you have had any welding done it might have knackerd the module...depends

both of my problem modules produced a spark
neither of them did it relaibly and that lack of reliability meant on some occasions the spark wasn't at the right time.

that certainly caused exceedinly bad running just about everywhere north of a reasonable idle

Pete came over and the utterance of "Your timing is all over the place dave" and as i was filling my lungs to say YEAH I KNOW, having checked out the mechanical side numerouse times.... that one comment kicked my brain into order and i put everything back as it was and tried another new module

Grins all round, just in time for beer o'clock


Dave