question on using Lucas

I recently went from 10w30 to 15w40 to see if it would increase my psi. Didn't seem to make much of a difference but the engine seems to be a bit louder now. Sounds like what some call here lifter noise/rattle at idle. I am thinking of adding Lucas to see if it will help minimize the noise. I'm in the northeast, so would adding a quart of Lucas to 15w40 make it to thick? Not sure if I should step down to a 5w40 first or does it matter?

You are entering winter and you raised your viscosity. Most choose to lower it to maybe 5w30. You may want to think about flushing your crankcase with a Flush product or drain some oil out and run a couple of quarts of ATF for 5 - 10 minutes at idle, then change the filter and refill with 5w30. Of course you could pull the valve cover and take a look with the engine ideling.

what is your oil psi?

I'd go down rather than up, and as long as your oil pressure is within range be satisfied. If the noise is piston slap, common enough on 4.0's, it won't be any better with thicker oil or better pressure.

IIRC he has an oil pressure problem, which is also why he is raising the viscosity, not just the noise problem.

Is it noisy cold at start up, or hot, or both?

Have you tried the 3800 rpm in Park for 45 seconds trick like I suggested?

Adding Lucas helped me quiet mine down before I learned about running at 3800 rpm to loosen up the lifters (or what ever it does).

2000, cracked head, 10 psi hot, confirmed with mechanical gauge. Head swap, new gauge sender, pressure fell to 0 while driving. Wrap it up to 4K and do whatever it does. Yep. That's what I'd do if it was a few thousand dollars of my money on the line.

Appreicate everyone's response...

Is there a risk in running my engine at 3800 rpm for 45 seconds as suggested? Could it get worse?

Is Flushing the engine a good suggestion or with a high mileage Jeep 145K may create more issues? I don't what to risk clogging the oil pump but do like the thought that it could clean out some of the crude.

At this point I may drop a qt out and add 1 qt of lucas to see what happens first.

Engine flushes can kill an engine if the crap comes loose in large chunks. It needs to be slowly, and carefully over time with a mild additive, but I would not do a flush on an engine with low pressure, as it might go even lower!!!!!

The 4.0s are hard to kill. 4000 rpm is not in the red zone. IF the engine self destructs at 3800 rpm it was about to self destruct anyway IMHO.

Mine had been run for years at 750 to 1300 rpm due too a bad TPS, and got dirty and noisy in the process because it was never pushed to the 3000 rpm range.

All I know for sure is it has fixed two of my renix engine noise problems for about 2.5 years now, including one with low oil pressure that already had a high flow pump and new crank bearings installed 5 years ago, now has 278,000 miles, and now runs smooth as glass after using 3800 rpm trick several times.

An engine flush could cause leaks too. Carbon builds up inside of engines when oil reacts to the hyrocarbons during the combustion process when the engine is running. The carbon likes to build up near the front and rear main seals which become hard with time. A engine flush contains chemicals that will literally strip the carbon/sluge out but it also cracks the rubber seals resulting in massive oil leaks.

Use Marvels Mystery oil first to clean the varnish from the lifters. You will have to add a Qt of Marvels with your oil, but do not over fill. This is a slow process and make take a couple thousand miles of driving to circulate enough oil through your engine to disolve the varnish. Once your lifet noise is gone. Use motoroils that are detergent based to keep you engine clean or the noise and varnish will come back.

Beats flushing your engine only to tear it down to replace the main seals because it is hemoraging oil all ove the place. Plus if you have ever replace main seals before, they are a pain in the ass to do.

So I already purchased a bottle of Lucas.. does it not remove the varnish on the lifters like MMO suggested? how do the 2 differ?

Sandydog said:

So I already purchased a bottle of Lucas.. does it not remove the varnish on the lifters like MMO suggested? how do the 2 differ?

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MMO is very thin and will lower the oil pressure and oil viscosity, Lucas does the exact opposite.

MMO is also a mild engine cleaner, Lucas is not. I suspect your engine may already be somewhat clean from running water/coolant mixed with oil already from the cracked head, blown head gasket?

In the long run you should drop the oil pan and install a new high flow oil pump. They are not expensive. I suspect the oil pump gear lash tolerance dropped from wear when the coolant got in there. And now it is too slopy, loose, to build enough oil pressure with hot oil. Add to that some increased wear in the crank bearings (which are easy to replace with the oil pan removed as well), and you have 10 psi hot at idle oil pressure.

Lucas may buy you some time on the oil pressure. I had more lifter noise with MMO, than with Lucas oil, but only the 3800 rpm operation ever fixed the noise problem on both of mine. Some times the noise comes back, if the engine sits up too long, but always immediately goes away after 30-45 seconds of running around 3800 rpm.

I lost an engine, and an oil pump using and engine flush cleaner once.

Have you tried the 3800 rpm in Park for 45 seconds trick like I suggested?


I did it for 3 minutes per another thread. No problems.

I have not tried the 3800 rpm suggestion yet. I added a quart of Lucas and haven't noticed much of a change on the oil pressure. What I continue to also have is the noise which is not there when I turn the jeep on but starts about 30 secs later. Sounds a lot like a diesel engine. I don't recall noticing this noise when I had the 15w30 running... Maybe it was but with the 15w40 it is definitely noticeable. Reading through th forums, seems piston skirts, faceplate, lifters, rods, bearings are all suspect. I can't seem to pinpoint the noise. I am willing to change the oil once more.... But not sure which way to go.... Up to a 50 weight or back down to 30 with a little Lucas. ... I am about to throw the towel in on the jeep.-

Gotta ask. What brand of oil filter do you have on there? Is it orange with black trim by chance?

Sandydog said:

Appreicate everyone's response...

Is there a risk in running my engine at 3800 rpm for 45 seconds as suggested? Could it get worse?

Is Flushing the engine a good suggestion or with a high mileage Jeep 145K may create more issues? I don't what to risk clogging the oil pump but do like the thought that it could clean out some of the crude.

At this point I may drop a qt out and add 1 qt of lucas to see what happens first.

Click to expand...

personally, i wouldn't be worried about having 145,000km on your jeep unless it's been ravaged on it's whole life, my jeep is currently running strong at 290,000+ km (no rebuild as of yet), it's been off-road for a majority of it's life an i still drive it through rivers, perhaps if none of these tricks work i'd test my oil sending unit? that could be the problem there, i had a 1990 ford bronco with an erratic oil pressure issue and that's what it turned out to be

He has already replaced the oil pressure sensor, and checked the oil pressure with a gauge, and no he is not using a Fram oil filter.

I have heard some people complain about engine noise that came when they changed oil brands, and left when they back to the original oil.

IIRC you went to a diesel oil (Shell Rotella?) with detergents versus a gas engine oil? But you did not mention what the API spec on the original oil and the current oil was, or is???? API SN, SM, SL or CH-4 plus.....? Also I don't think you answered my question as to whether you switched to synthetic, or stayed with old style dyno (non-synthetic) oil?

Most of today's oil is not what it was a year ago, or 2-3 years ago, as EPA has been mucking with the allowed ZDDP content in the oil, and has focused on the new style engine internals, versus our old style engine internals.

Keep in mind that a new oil pressure sensor could get clogged with junk, causing an error in the reading, so a recheck with a gauge may be of value.

Also what is the idle speed, the lowest idle speed????? IF it is under 750 rpm, that lowers the oil pressure when hot a whole bunch!!!

OEM JEEP spec is 13 psi minimum, hot idle in park at 750 rpm IIRC.

Get me these answers before I comment on going back to old oil!!!!!!

He has already replaced the oil pressure sensor, and checked the oil pressure with a gauge, and no he is not using a Fram oil filter

How have you determined this or am I just blind when reading the thread?

He had started another thread on which oil to use to hide the low pressure problem. No, he has not stated that he verified good oil pressure with a mechanical gauge after the last drive that showed zero. He has said it's been running and not showing any additional pressure, but I don't know if that means 10 like before, or 0. No follow up as to whether they'd checked the new sender yet either.

Sandydog said:

So recently replaced the cylinder head on a 2000 Jeep with 145K miles that I purchased.

Got low oil pressure.. confirmed with mechanical gauge. 40psi at cold start, 10 psi at warm idle, 20PSI at 1600 rpm. (I already swapped the oil sensor - no change)

I went from 10W30 to 15W40 with no noticeable increase in PSI but do feel the engine is a bit noisy now. (used Rotella 15W40 with a Napa gold filter).

I was at a shop today and a guy suggested I go with a synthetic 20W40 - I'm in the Northeast, but he said synthetic starts as water and thickens as it warms up, standard oil goes the other way starts thick and thins with heat. Is this accurate? As you can tell I am clueless - and here I thought oil is just oil.

Sandy

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Sandydog said:

Sigh!

So today my son took the Jeep for a short ride and returned telling me the oil pressure went to 0 psi and the check gauge light came on.

Am I totally screwed at this point? Although the low pressure was low it was at 10psi at worst. Would it just go to zero in a matter of a day? I had 15w40 with a Napa gold filter. I had the oil sensor changed a week ago. Could an oil pump fail like that? Help.

Click to expand...

http://www.naxja.org/forum/showthread.php?t=1074624

He had started another thread on which oil to use to hide the low pressure problem. No, he has not stated that he verified good oil pressure with a mechanical gauge after the last drive that showed zero. He has said it's been running and not showing any additional pressure, but I don't know if that means 10 like before, or 0. No follow up as to whether they'd checked the new sender yet either.

Did that thread say he wasn't using a Fram then?

Edited for link. Diesel oil and a Wix filter, 10 psi hot.