Random engine wobble or shake occurring (1 Viewer)

[NOSAJ]

2001 lx470 with 278,000 on the clock. Just got back a 3,000 mile trip out to Moab and back. Did a ton of pm a few months before the trip including new spark plugs and replaced a bad coil. Drove into town this morning 40 minute drive. Got into a parking place and truck was idling fine for a few minutes while I was checking emails etc. Then truck started vibrating excessively shaking wobbling pretty bad like a motor mount was broken or something. Popped the hood and the engine is wobbling. I got underneath and everything looks fine. No misfire or running rough just wobbling/shaking. I didn’t see a broken motor mount. Then after a few minutes it smoothed out. Then it will come back a few minutes later. It doesn’t matter if I change gears forward reverse etc. I’ve revved the engine a little to see if it changes and nothing. Just shakes more as rpm increases. Then it will just go away on its own. No cel yet. I’ve driven around the block a little and will be fine for about 5-10 minutes. Just appears randomly and goes away randomly. At this point I’m thinking bad harmonic balancer, motor mounts, spark plug, loose spark plug, or possibly another bad coil. Super thankful we made it back home when this occurred. Let me know if anyone has any other ideas or seen this. I’ve searched and can’t find this exact issue yet.
Thanks! Jason

 

[KliersLC]

Sounds like a bad coil to me. When I lost one I didn't have a CEL for quite awhile. Easy way to determine if it is a misfire issue vs something else--is the power reduced while it is shaking?

 

[NOSAJ]

Thanks for the response. I believe/hope you are correct. It’s really hard to tell if it is loosing power because the vehicle shakes and vibrates so much during the episode. I got it home yesterday going the interstate and it did it a couple times during the trip back.

I’m probably going to replace all the coils, and check all the spark plugs while doing that and order new motor mounts. I figure it’s time to do that with that many miles and see what happens.

 

[2001LC]

1. See OM in regards to prolonged idling. "Don't do it"
2. Use tech steam to check for misfiring cylinder(s)
3. Watch out for Chinese "boot leg" spark plugs and coils. Lots of junk on the market, these days
4. Keep eye on engine coolant temp and fuel trims.
5. Spark plugs are only a portion, of a good tune up. Get basics inline, especially vacuum and air intake.

 

[Peter S]

Couldn’t be an engine mount if you were parked as these engines idle so buttery smooth.
I would also vote it’s a bad coil as a misfire causes the engine to be out if balance and feel like a wobble.
When I had a bad coil it didn’t set off the CEL until it was very severe.

 

[NOSAJ]

Thanks guys! Only used Toyota parts bought at local Toyota dealer or McGeorge. Definitely wasn’t idling too long in my opinion. Thanks again. I’ll report back.

 

[NOSAJ]

So the truck has been sitting waiting for coils to arrive. Finally got the coils last Saturday. I started the truck up a couple of times just to check and the times I started it before coils arrived it is constant now. No random to it now As soon as I start it the engine shakes pretty bad.

Took out the old coils and 3 of them looked pretty bad. Some were even cracked a little and one discolored. So I thought yep got to be a bad coil or multiple coil problem. Got the new coils in and immediately the engine is shaking. Shaking so bad I don’t want to run it long. So next I’m going to check spark plugs then injectors. Visually everything looks fine as far as vacuum hoses. A mechanic friend told me to run a temperature check on the exhaust manifold and I might be able to narrow down which cylinder is acting up. Question is will tech stream tell me issues if no cel?

Thanks!

 

[BullElk]

Use an OBD reader and check for a pending code that hasn’t thrown a code or CEL yet.

 

[2001LC]

A though just occurred to me. "Fan Clutch"

They'll go bad and often freeze up, work than freeze up again. They can freeze at an angle and shank engine very badly.

Try spinning by hand.

 

[NOSAJ]

Thanks guys I’ll try that. Also wondering maybe bad gas?

 

[KliersLC]

Bad gas could potentially cause that, but it is more likely to be a misfire. If you don't have an OBD reader to determine which cylinder(s) are acting up, start the truck and while it is running, unplug the connector on a single coil pack. If the truck runs worse, that cylinder is verified as good--reconnect the plug and repeat on the next coil pack. If the truck runs the same, you have found a)the problem cylinder, or b) one of the problem cylinders.

 

[AlpineAccess]

Bad gas is unlikely.

If you took coil packs off and put new ones on and the leak became much worse, I'd trace back your install to make sure you put all of the vacuum hoses back on correctly, and that your coil packs were installed properly.

Temp checking the exhaust manifold is an interesting recommendation when an OBD2 reader will tell you what cylinder is misfiring.

 

[BnvS]

Bad gas is unlikely.

If you took coil packs off and put new ones on and the leak became much worse, I'd trace back your install to make sure you put all of the vacuum hoses back on correctly, and that your coil packs were installed properly.

Temp checking the exhaust manifold is an interesting recommendation when an OBD2 reader will tell you what cylinder is misfiring.

Also Techstream will be helpful in finding out Misfires as well. Search up YouTube on Techstream and Misfire and I am sure you'll find the informative video.

Had a similar thing happened to my Tundra. My end issue was spark plug gap was misadjusted.

 

[NOSAJ]

I appreciate all the help! I think I found the issue. Thanks to @2001LC for mentioning the fan clutch. In thinking it was a misfire or vacuum hose I hadn’t even thought of looking at the fan clutch etc. Well it’s not the fan clutch it turns fine but surprisingly the fan has come apart. 3 of the 7 blades are missing 2 others are cracked and in bad shape. I have no idea how we didn’t hear anything or how it did take out radiator or something else. Ordering a new fan!

 

[2001LC]

Don't just pass fan clutch (FC) and or fan bracket (FB), as good. The vibration set up by fan blade, can damage FC and or FB. Due to vibration and wobble. Either FB or FC failure, often damage the other. So a blade failure may have damaged both. Same holds true of any 1 of the 3 (FB, FC or blades) going bad. Each can effect the other. Plastic fan blade, is least affected by others.

Just because a FC spins easily by hand, doesn't necessarily mean it's good. It's cheap to replace FC, at same time as fan blade.

Check FB closely. Its more labor intensive to replace at this time, but will be more after new fan blade in.

Try this to inspect FB:
1) While drive belt off. Spin the fan/FC/FB assembly. The whole assembly spins easy with belt off. It should spin as one unit. That is; all components at same time and speed. So that what is actually spinning, is the fan bracket shaft on it's bearing. If you hear any sound as fan spun by hand. FB is bearing is bad.

2) Grab FB by the pulley, if pulley off grab at pulley mount point of/on FB. Try to move FB, up and down. If any movement "ANY" play whatsoever, it's bad.

Either or both 1 or 2 fail, replace the FB.

 

[NOSAJ]

Thanks I’ll test. fan bracket is less than year old but I’ll double check

 

[abuck99]

Did you run through any water crossings on your trip? I’ve seen a few broken fan blades from “spirited” water crossings.

 

[NOSAJ]

So after 8 months the wobble is slightly back. Looked at the fan and 8 month old Toyota fan is broken again. 8 months ago I replaced the fan and the fan clutch (Toyota). I am now thinking that the fan bracket is bad. Fan bracket is Napa and is a 1 1/2 years old. I did the fan bracket test that @2001LC suggested and seemed good when I replaced the fan and clutch 8 months ago. Ordering a Toyota fan bracket and new fan today. Let me know if anyone has any other ideas? Not sure what else could be breaking fans? Not doing any spirited river crossings.

 

[2001LC]

Very likely fan bracket, is bad. A stethoscope can be useful.