I just got my 258 back in my jeep after a rebuild... Mechanic that rebuilt it for me said that the weber carb that is on it is almost shot and the fuel pump was bad so it dumped a lot of fuel into the block... Now it gushes white smoke! He tells me that he cleaned up the carb and replaced the fuel pump. He also is telling me that I need to just put some miles on it and the smoke will clear up. Is this true? He said the engine just needs to work out the fuel that is in the rings and seat themselves. I asked why all of this? And he said that everything went well with the rebuild, the carb is tuned good and the timing is spot on. Should I be worried or should I just drive it ? How long should it take to clear up???
I would be checking the oil for water. Also check antifreeze for oil. Sounds like bad head gasket. My brothers ran great but the gasket was bad from cylinder to water jacket. Combustion gas was getting in the antifreeze. It sounds likes yours is burning antifreeze. What does the exhaust smell like. If its a sweet smell it antifreeze.
1985 cj with 1992 wrangler body.
Its's a project for now needs more parts and money.
258 in-line 64 speed 4' lift
It doesn't smell bad at all, just white smoke. Head gasket was replaced head was redone. No oil in antifreeze coolant is fine. It also blows smoke out of the pcv breather out the top too. He said the oil was really thin due to all the gas in it but he changed the oil and filter. The compression is good on all cylinders also. So far it only has about 10-15 miles on it since I got it back. Could it be that I just need to put more miles on it and let it clear up itself?
How many miles you have on the rebuild. Does the smoke smell like flooding, or burnt oil. Is there excess water commingle out of the tailpipe. If you don't have oil in the water, or the other way around. The way I was thought to seat rings, is to put it in first gear while driving down the street or lonely highway. Take it in gear, slowly up to 4000 rpm and let up til it come to a rolling idle do that 5 or 6 times and that will seat the rings. The break in period after that is about 500 miles. I've also heard another way to do it, is you should drive 35 MPH for 20 min. 45 for 20min 55, 65, this will also break them in. Also keep an I on your oil level. Or drive like you stole it if its under warranty, if it comes apart , its not your problem if he said your engine was fine.
Here, hold my beer and watch this SxxT
Ok I'll try that! Thanks, I guess I needed someone else to tell me that so I can believe it. It sounded kinda weird when he told me all of this but ok... Ill just drive and put a bunch of miles on her. Thanks
My rebuilt 258 don't smoke at all, something don't sound right. I broke in my new cam for 20 minutes at 2000 rpm and everything is fine except a oil leak, all my rings seated and it runs awesome, I would replace the carb if it's a pos and maybe look for a different mechanic. I wonder if he sprayed the head gasket with copper coat that stuff helps seal a lot never had problems with it.
1981 jeep cj-7 258 with t-176 4 speed and 31x10.5x15 tires,
1979 jeep cj-5 gone but not forgotten
Apparently the motor didnt smoke at all right when he put it in but something then went wrong with the pump and it and the carb dumped fuel into the block... Then made the oil super thin so he changed oil and filter.starts and Idles good and when warms up it runs good just smokes like a train. I can tell that gas is in exhaust due to a drip from tailpipe.
Im sorry I didnt catch it was a post rebuild problem. if you have a manual trans, then you must have a head gasket leak or an exhaust system full of moisture . If you have antifreeze in it and the head gasket is leaking the exhaust will smell sweet and if you pull the plugs the real clean one will be the cyl. with the leak.