Big Bang, need theory

[balloondoc85]

RE: Re: DISASTER NEED HELP

Jeep Wrangler, manual trans, no AC, 4L, 1995, 80k miles. Driving on highway, big bang, then oil smell, then LOUD knocking noise which gets faster with increased idle speed or foot on gas. What is it, please help, Jeep at dealer this morning, will I get ripped off?

 

[90Xjay]

First welcome to Jeepz.com :lol:

When you first heard the "big bang" and smelled oil did the engine die or lose power?
Did you see any oil dripping from the engine area?
Did it start billowing smoke from the tail pipe?

So many things it could be, broken timing chain/belt (not good while driving.)

burned piston

I don't know about your dealership habits or references, you might check with your local BBB to see if they have any unresolved customer complaints...

Keep us up to date. Sorry to hear of your misfortune, the 4.0 ltr is usually one tough motor and very dependable up to and past 300K miles in most cases...

Good luck..

90

 

[Sparky-Watts]

Big bang and oil smell can't be good....especially with the knocking sound you hear afterwards. I have many of the same questions as 90xjay has. Where in the engine does the noise come from, top or bottom? could be a pushrod, slipped bearing, broken piston, etc.......bet it ain't cheap, whatever it was.

 

[Bounty__Hunter]

RE: 4.0 Rebuild

Sounds like a busted piston, but who knows. Either way, you're going to get ripped off because you took it to the Stealership.

 

[DerekC]

I have to agree with the others, sounds fatal...and expensive. Since it is already there, you may want to see what the dealer says is the problem, will most likely have to pay an hours diagnostic charge, then get it out of there and to a reputable independent or home and break out the midnight oil. This is coming from a Toyota DEALER technician.

-D-

 

[cool_p]

Re: RE: Check out this Wrangler on Ebay

I have experienced a similar occurence.Original owner, 95 YJ 4.0 Auto, 74K. 70 to 75 MPH, oil pressure 55 to 60 PSI and coolant temp 200 to 210 F. No noise or vibration to indicate an impending failure. It appears that the engine threw a rod. If anyone has experienced this failure or if anyone KNOWS of someone who has had this failure, please contact me at cool_p@earthlink.net. Let's see if this is a common problem.

 

[balloondoc85]

Big Bang

You are right, to an extent. Everyone seemed to indicate that I likely "threw a rod", including my girlfriend, seems she and her dad are smarter at engines than me. The initial expected charges from the dealership were around $4000 (like you) for a new engine. Then they called and said that it was actually a spark plug that had "popped" out of the engine and it could be fixed. They re-threaded the hole of the spark plug and seated a new one. Good luck for me...charges were $200 total! They had not really seen that happen before. Best of luck. Let me know if I can help more...

 

[Sparky-Watts]

um... yeah.... this is a mockery to the jeep name

Interesting! I remember riding with a friend in his 60's model Chevy PU years ago when he blew a spark plug out. It made a pretty big bang, and of course the engine started running rough and we could smell oil and gas mixed together afterwards, so naturally, we both assumed he'd broken a major component in the engine like a piston or rod, until we got it pulled over and looked under the hood! Man, I hadn't thought about that incident for at least 20 years until I read your last post!!

 

[odjeep]

RE: Re: RE: black Bikini Top for YJ

had that happen on a cub cadet with a 8hp horizontal briggs. the hood was taken off cause it got smashed, fiberglass, was about 15' away from the shed heading toward it and heard this loud bang, like a gunshot, and then sounded like a rock hitten the shed. turns out the plug had worked loose. just my little story for the day.
od

 

[Sparky-Watts]

RE: Which frame is better to repair?

had that happen on a cub cadet with a 8hp horizontal briggs. the hood was taken off cause it got smashed, fiberglass, was about 15' away from the shed heading toward it and heard this loud bang, like a gunshot, and then sounded like a rock hitten the shed. turns out the plug had worked loose. just my little story for the day.
od

I can just see the headlines now: "Man Killed by Spark Plug. Police Looking for Half-Mowed Yards." :lol: