Loose engine

Hi all.
I have a 1987 XJ with 260K miles. Runs good no troubles (a little rough not bad) however at start up and at high RPMs (I try not doing except for having to get on it to get on the highway) The engine tends to rattle. Guessing it is the pushrods and valves? I am worried that at some point in time a push rod is going to shoot out the Block.

Question........I cant afford the engine rebuild and I am not set up for an engine swap. If I was to replace the Head (reman. or new) and put in new pushrods.....would this help me any.....buy me some time?

Its probably just worn/sticky lifters. An oil flush product may help if its sludged up. If they're colapsed new lifters should cure the problem and make it run way better once the valves are opening all the way again! You can check valve lash to be sure but this is common on these motors. I would do this first be fore pulling the head. Push rods are most likely still good, but check them too. Give this thread a little time and see what others have to say...but this is my best guess!!

Clean out the motor, either with a flush which is fast or switch to Mobil-1 synthetic, it will clean it out but not quite so quickly. When you do this, either one, keep an eye on the dipstick, in the case of the flush it will continue breaking down the stuff for a while after you refill with oil. Once you can't read the dipstick thru the oil on it change the filter.
I think 87's also had a knock sensor on the drivers side of the block between the exhaust header and the block, I'd check that if what you are describing is knocking and not valve train noise..

Thanks for the responses. I was planning a oil change this weekend. Maybe I'll flush it. I have never used a flush before. Any Brand better than others....anything I should look for while flushing?

Mudweiserjeep said:

Thanks for the responses. I was planning a oil change this weekend. Maybe I'll flush it. I have never used a flush before. Any Brand better than others....anything I should look for while flushing?

Click to expand...

There are a bunch of them out there, Bardhal has been around the longest. You just dump it into the old oil, slap on a cheap oil filter and follow the directions. I'd probably change that filter once more during the process.
Others have used 'seafoam', ATF, Kerosene, etc. I think the seafoam you can dump in and drive for a few days or so, ATF and Kero you need to be careful with, don't take the engine above an idle while it's in there. After any of those cleaners though, I'd do a quick cheap oil change after dumping the mix out, oil and filter change, run for a half hour or so and then do a good oil change.

If your using those flush's, I would be very easy on the load of the engine, depending on how much the flush thins out the oil.

ATF, has the same base stock as motor oil with a different additive package, I've driven around with it and NOT seen any damage. Still, NOT to the time to Hot Rod, 4Wheel, Thrash your motor when ATF is in the oil, drive it easy. Marvelous Mystery Oil seems the same as ATF. Some other additives that or more oil like, you can drive around.

Kerosene, SeaFoam, GUNK Engine Flush (I think its just a quart of Kerosene re-labeled) all recommend that you only idle the motor for a little while with it in it. Make sure you follow those instructions (well Kerosene won't come with instructions, but you get the picture), this stuff thins the oil out a lot, I would NOT consider it safe to drive with this mixed in the oil, just let idle for a half-hour.

Just wanted to update. I used Gunk's Engine flush. Said to add it to oil with the engine cool. Run for 5 minutes at idle. I ran mine for 20 minutes. Drained the oil and changed the filter. The oil was definately blacker than it was before I started. I havent put very many miles on it yet so I havent notice really any difference. The oil is still clean looking. I am going to keep monitoring the oil and I am planning on the next oil change to flush it again. The Gunk bottle said for engines with 50K plus to do the treatment twice. I figure I will do it again next oil change.

I done K-1 flushes at almost every oil change. Cheap smiple and effective. It gets my volt.

here's a question, not stealing the thread, with higher mile engines like this one, mine has 207k on it, is there any particular oil that would be best to run after doing a flush? since you get rid of a lot of crap, you loosen a lot of things up that aren't used to being so loose. is it wise to NOW use a different oil? and what kind oil would suit the best?

There are goods and bads to changing oil brands. Pretty much all of the brands have the same base consistancy but there additives that they use can cancel each other out a little. I alway have changed at 1000 miles after switching brands. You could run something a little heavy in there like a quart (of the Same brand and style of oil) of 20w50. I put seafoam in for about 500 miles with some 20w50 after my first oil change in mine and it got alot louder. sounded like all of my lifters were floatin and the valve were stuck. Does anyone know if the 4.0 is an interference engine? Kinda off the subject but thought I would ask?