m20 engine smooth but feel tremor/shake through steer and bo

[markus_74]

Hello, Friends

I got another problem, initially I think it is propshaft balancer that shake, but while my car stop I still feel tremor through my steeringbwheel and car body.

Car still smooth but I feel may be some tremor and linear with more rpm. It feels like pulse it is regular but more follow rpm.

May be misfire?

I have open and check.all spark plugs Is OK, clean all injectors.

Put back.all together but still same.

Does is it cause by valve setting may be it is time to adjust?

Or another cause?

Thank you
Markus

[Brianmoooore]

An inline six is an inherently smooth engine - so smooth that a misfire on one cylinder is barely noticeable.
Pull off and replace the plug leads one by one, and see if one of them makes no difference when off.

[Yeti]

if the steering wheel is juddering its proabably wheel balancing

[Brianmoooore]

if the steering wheel is juddering its proabably wheel balancing

I was assuming this was with the car at idle and not moving?

[markus_74]

The car at idle.

I have try pull off 1 to 6 ht lead but still can not locate which one has problem.

I have spare ht lead and will try to replace it this morning.

[markus_74]

Today, have change ht lead still same, change distributor still same, change and check spark plugs and still same, try another ecu and still same.

Yesterday I have clean injectors manually with carb cleaner, really dirty with black gums although it only ran 10000 mils.

It feel some rough pulse like 1 piston not working properly.

What else should I check? Replace with new plugs? Or replace all injectors or compression test?

Need advice.

[Brdjo]

Maybe compression test will be fist think to do, just to know with what you dealing with... Make sure that your engine makes ok compression..

1.Warm up car to operating temp.
2.Disconnect distributor cable.
3.Remove 1st plug.
4.Connect the gauge.
5.Crank the engine with full throttle press, 3-4 engine rotation.
6.Write down the value.
7.Put plug back in.
8.Go to next cylinder.

[markus_74]

How about bad injectors? I just tried pull off one by one injectors connector and I feel the pulse is nearly same but with more shake, I have feeling that may be bad injectors?

I will do compression test next as I dont have the tools.

Do I should crank the engine with hand or engine starter ?

[Brdjo]

You can send all 6 injectors to someone who can test them and celan, after you done compression test and make sure that engine makes ok compression.. any mechanic shop can do the compression test for you, write down value for every single cylinder, you are looking for consistency between the cylinders, no more than 10% difference between cylinder is ok..

Crank the engine with engine starter..

If you crank #1 cylinder 5 times, all cylinders must be cranked 5 times.

[markus_74]

Compression test (warm and 6x crank)
Cyl 1 160psi
Cyl 2 165 psi
Cyl 3 160 psi
Cyl 4 125 psi after add oil 160 psi
Cyl 5 120 psi after add oil 170 psi
Cyl 6 140 psi

Does is it make my engine pulse/smooth shake? Or still another cause? May be injectors?

Engine only run 10000 mil after rebuilding/re boring from m20 b20 block.

Is it worn piston ring? Or machine shop wrong while doing reboring?

The honing pattern is absoluty wrong because of the degree not 45 but nearly 180 swirls.

But this symptoms become worst recently, I mean while the engine starting life it is only smooth pulse.

What should I do? Change piston rings? On Cyl 4 and 5 or...

I avoid change the block.that cost me really huge.

Car run fine, no smoke, no excessive oil consumption, only engine pulse/shake not balance

Thank you

[Brdjo]

Cyl 4 & 5 have some kind of problem, first guess will be "worn" compression ring... my suggestion will be to go to the man who did mashing and assembly on low end block..

I think that kind of difference can make engine shake (maybe not so much to feel thru steering wheel), but wait for someone else opinion on the subject..

[Brianmoooore]

A leak down test would give further information. Obvious thing when two adjacent cylinders are down is a gasket leak between them.

[markus_74]

How to do leak down test? Is it that use compressor and two gauge?

Water not less, and oil not mixed with water.
No burn oil in the exhaust.

[Brdjo]

Nevertheless, still can be a head gasket leak...

[Brianmoooore]

There's very little meat between the bores on a M20B25, and the gasket at that point is nowhere near any water or oil ways.
Yes, leak down test is with compressed air and two gauges.

[markus_74]

But I have tes with adding some oil into spark plug hole and compression raising a lot, does is it assume that piston ring or worn cylinder wall?

But it is my fault not test it while I just rebuild it, so I can know if machine made mistake while reboring, I mean the gap is too big.

I want to change piston ring but afraid if it is not fix it or may be with more hard piston ring so can compensate the gap between piston and cyl wall?

[Brianmoooore]

Some of your added oil might be finding its way into the hypothetical head gasket leak as well, temporarily sealing it.
Get the compressed air into 4 or 5, and listen in the adjacent cylinder to hear if it's leaking through. Compare with two of the known good cylinders.

[markus_74]

In case it is head gasket leak, how do I fix it? Just replace it with new gasket to fix?

How much psi of air from compressor? Does small compressor can do this job?

The position of piston while to do test?

I will try find on the Web how to do this work.

Thank you

[markus_74]

Just take car at journey now, I feel vibration is more while car in very hot condition at traffic jam.

Or is it the fan blade not balance/crack?

[Brdjo]

anything new?

[markus_74]

Yesterday I take all injectors to test the spray pattern and consistency and I found 1 spray pattern to wide and 1 has bad consistent the direction of spray is change eavery time. But I have not install it yet so can not tell the difference.

I also want to check may be there are air leaked in the intake gasket etc.

But can it because of my camshaft is not very good laid into the house, I mean because of the cyl head is used and also camshaft so there is a gap between cyl head and cam? So the rotation of center distributor slightly not center?

Or any advice?

[markus_74]

And on cyl 5 cam shaft lobe? I see a worn not too deep but it is the only one that worn, does is it cause the different compression or vibration?

I will try to adjust all valve to 0.25 first and try it will cure or not.

[ChrisHC]

Could there be any connection to the other problem markus has posted about, a dubious quality water pump which has a poor blade? If the water pump is unbalanced, could that cause engine vibration?

[markus_74]

I think vibration has occur before and after I changed the water pump.
The old waterpump is skf that I buy used one and only last for 14000 kilometers.

[reggid]

You need to find out what the problem is with leakdown test mate. Based on that remedy as needed.

[markus_74]

Found cyl 5 and 6 the rocker adjuster (out) is way too loose and the small hole in the rocker has twisted to inner side.

I have change both of it and will try tomorrow.

[markus_74]

Have tried to start the engine but vibration still.

May be it is the compression that is different between at Cy 4 and 5

[markus_74]

You need to find out what the problem is with leakdown test mate. Based on that remedy as needed.

Yes, I think I should go that, but no mechanic here has.ability to do that.

[markus_74]

You need to find out what the problem is with leakdown test mate. Based on that remedy as needed.

Yes, I think I should go that, but no mechanic here has.ability to do that.

[markus_74]

I have an idea, that may be my vibration damper slightly damaged?
What is the symptoms of broken.vibration damper?

My car vibration is only at idle that is 600rpm to 1500rpm that at 1500 is the most vibration and after that 1600 goes up is. Smooth no vibration ar all.

And while the car just start from cold it feel more vibration and after my car hot vibration is reduced but still there.

And if the worst case it is not vibration damper and the suspect is certainly compression lost.

How to fix it? Just replace head gasket or buy new block and reboring?

Thank you
Markus