I’m going to try and be as detailed as possible for everyone who may be able to help. Please fully read as I did say a lot here. THANK YOU!! anyways yes, stupid me, I know. My oil sensor light seemed to fail me this time. So.. I was driving and all of a sudden there was a very loud flappy/spitty knocking kind of noise , almost as if there was a rubber flap in the wind along with white smoke spewing from under the car. I pulled right over , checked the oil, and topped it off.

The next day I was driving the same noise occurred without the smoke. I pulled over to inspect and I also noticed a vacuum hose right by the fuel rail that was disconnected so I reconnected it (this could be irrelevant just figured I’d mention.) The car made the same weird knocky noise about 3 times again. On 2 of those occasions, I had my defrost on and the noise occurred, it oddly went away when I turned the defrost off and I kept driving as normal. Now, I pulled into a parking lot and the car suddenly locked up as if it threw its self into a safe gear. Even if you were to floor it, it wouldn’t have moved much or maybe not moved at all, I just didn’t want to cause any more damages. I’m aware of limp mode but this car is not driveable at all in this condition.

**REWIND a couple days ago, yet still after the car initially broke down from no oil, I replaced the valve cover gaskets. I noticed a puddle of oil in the valve plate pooling to the passenger side… might be normal? I also believe I may have put too much oil into the car after I initially broke down. And potentially could have been riding around with too much oil but there wasn’t any major oil leaks nor any white smoke. After the car broke down in the parking lot, I drained the oil from the pan and cleaned out the oil in the spark plug holes, and yes there was a good amount of oil on some of the sparkplugs and in the holes 3,4,5, and 6. So I drained the oil , cleaned plugs, dried holes , put it in drive and it would go but then aggressively lock up. I re parked it and tried putting it into gear and the car wouldn’t move, same with reverse. If I was to cut the car off and turn it back on it would drive and then lock up again.

It starts and idles just fine. Hopefully I added enough detail and stuck to the point I’m just stumped on this one, not sure what to do next. Anyone who responds to this is a major help!!!

 

Ouch! Whatever is going on, ouch. First off, I really like that color. It seems to work well with the cars shape.
The first time this happened, you say you topped it up. I assume you mean engine oil, but how much did you put in? And what did the dipstick read beforehand? Have you had to add oil as an ongoing problem with it in the past? If so, can you tell where the leak may be? Oil in the spark plug holes is what I'll call a design flaw and seems not that unusual. Oil will sit in the right side of the head as it is lower on that side.
Also, have you checked the transmission fluid level recently? and where does it sit? Have you needed to add to it before?
If you look in the coolant reservoir does it look pretty and green? preferably with no oil sheen....
And of course then next most important question- have you done any work on it that may be the cause of this problem? Maybe something as simple as rinsing the engine bay while washing and possibly knocking a hose loose.....
I feel like if you have damaged the engine then it wouldnt run right or at all. But if it will run but not move then it must be more of a transmission problem .....or maybe brakes... Your hand brake isnt on is it??? (That just occurred to me. ) Maybe get under it and check your U joints in the drive shaft and in the half shafts- there are 6 total i believe- to see if one has broken and may be binding up? I had one in my 66 that was so worn that it would let the whole driveshaft flap against the bottom of the car. What a scary noise.
Keep us posted, I hope its an easy fix.

 

Hi Matt,

Just to add to Jerry's excellent questions:

When you check the transmission fluid level, let us know how its color looks and if it has a burned smell.

If the fluid level is low, inspect for leaks at the cooler lines and raise the vehicle and check for leaks at the dipstick tube nut, fluid pan gasket and front & rear transmission oil seals. A front seal leak will drip fluid into the bellhousing. A rear seal leak will be evident around the output flange.

While you're under the car, check the gear shift cable linkage on the left side of the transmission. The screws that secure the cable bracket have been known to vibrate loose and fall out.

Cheers,

Don

 

Hi Matt,

Just to add to Jerry's excellent questions:

When you check the transmission fluid level, let us know how its color looks and if it has a burned smell. You may be able to visually detect dark particles of friction material in the fluid.

If the fluid level is low, inspect for leaks at the cooler lines and raise the vehicle and check for leaks at the dipstick tube nut, fluid pan gasket and front & rear transmission oil seals. A front seal leak will drip fluid into the bellhousing. A rear seal leak will be evident around the output flange.

While you're under the car, check the gear shift cable linkage on the left side of the transmission. The screws that secure the cable bracket have been known to vibrate loose and fall out.

You don't give us the year of your XJ40 so we don't know which transmission you have. It is helpful if you visit your User Control Panel and edit your signature to include the year, model, engine and mileage of your car so this information appears in all of your posts.

Also, I have edited your post to add some line breaks, since large blocks of unbroken text are hard on old eyes like mine!

Cheers,

Don

 

THANK YOU GUYS FOR RESPONDING SO QUICK. I seriously can’t express how much I appreciate it. Ok you guys aren’t going to believe this. My issue had nothing to do with anything I said. Im laughing whilst typing this, my bottom caliper bolt must’ve never gotten tightened and as I pulled into the parking lot the caliper got pinched and it was causing the front wheel to lock, I was assuming it was transmission related . I fixed the issue and it’s back to normal. Thank god this didn’t happen while I was doing 80mph…. Anyways my car still
makes a spitty knocky kinda of noise if I ride with the ac on after x amount of time … very strange

 

YES!!!! Another easy and inexpensive fix!!!!!
I am glad you got if figured out, since you obviously adore your car.
So, now to move on to the funny noises....