Advisory: Old Car, sticky valve-lifters and the MMO continuous flush

[BonzaiDuck]

I'm just posting this for benefit of someone driving an older car with valve-clatter or sticky valve-lifters.

I just had a family member who lives with us -- pass away. I'm the only driver left among us. With a modest family estate, we don't salivate over new cars, and we attempt to keep old ones running at somewhat a lesser expense.

Everybody knows that I'm proud of my 1995 Trooper LS, despite myths and an orphaned-model status since earlier in the millennium. Looking at my spreadsheet, it has been completely restored. 60,000 miles on a rebuilt tranny -- the only old components are the AC system (perfect), the power-steering pump and steering gear-box, fuel-tank and delivery hardware, and the engine. Everything is tip-top, parts are available, and it's a wonderful ride.

The engine has 192,300 miles on it. It never has a problem in smog-tests. Fuel economy is not the best -- more in line with what one gets running an older Jeep Rubicon or something like it. We had noticed a sticky-valve-lifter noise or valve clatter since 2004, When the mileage was 120,000. Adding a little extra oil attenuated the noise. The Trooper never burns oil, and all leaks have been eliminated. [The two formulations of Blue Devil "mainseal" and "engine-stop-leak" worked pretty well.]

A Repair Shop of Horrors and a Mechanic-from-Hell misinformed me about oil-change status, a disconnected vacuum hose and a broken PCV valve. The waste oil from the change at end of that year was . . . disgusting. Immediately and since then, those features have been fixed.

I determined to make an engine flush, and looked into the off-the-shelf options, of which Marvel Mystery Oil was one. The other flush-in-a-can products are only in the engine a couple hours and not meant for extended driving. MMO is just an additive you can put in the oil, change after change, and just run the car routinely.

I started with a half-quart of MMO, a half-quart of synthetic 40-weight with the remainder of 5-qt capacity filled with 30. For the summer of last year, I changed to 40-weight so that the MMO dilution gave me 35. I probably used a full quart of MMO. The engine has been run for approximately 3,000 miles with the MMO additive. It now starts cold with only the noise you'd expect for an engine just warming up. When the engine is at its full operating temperature, no noise at all.

I ran it by my Solid Gold Repair Shop, and asked their veteran Isuzu mechanic his opinion, assuming his ears are closer to those of Carol Shelby or Ken Miles. He thinks the engine is perfect, can't detect any damage from the sound of it. He put on his robes and gave my Trooper his pontifical blessing.

MMO advises to just use it with every oil change. Maybe they want to boost sales -- can't tell. I'll probably follow that advice, but I'll use progressively less of it through subsequent changes.

I just find it somewhat amazing, watching and listening to the engine over the last year. I notice positive changes in the valve noise over a week's time, and for the last month, it seemed to improve just for letting the car run in the garage for a couple hours every couple days between actually driving it. Each time I start it up, it's better.

 

[herm0016]

we had 2 box trucks for delivering doors and millwork. we would watch the fuel mileage and when it got to 7 or so, dump a quart in the fuel and a quart in the oil of one diesel and one gas engine. i think they were 50 gal tanks. The fuel mileage would go back to 10-12 on the next fill up. I put it in my diesel tractor along with power service to help with lubricity on the mechanical injection in every fill up.

glad its working for you also. i think doing it a couple hundred miles before every other oil change would be good, and add some to the fuel at that time as well.

some say its just snake oil, but it seem to work well for us and certainly saved us a lot of fuel on the big trucks.

 

[BonzaiDuck]

I'm in periodic, sometimes monthly contact with the service advisor at my "Solid Gold Repair Shop".

Here's the story, and I'll try and make it brief. Back in 2017, I was shopping at TARGET, came into the parking lot, and a fellow pulled up to me before I got into my Trooper. He was deaf guy, and he wrote down his conversation on a notepad. He wanted to know who services my Trooper. I told him I was doing a market-search for a new repair shop; told him not to go to one down the street; advised him to try "Pro-Trans" on the other side of town. This was before I finally took my car to them ("Solid Gold Repair Shop") spring of last year. Then, I ran into the same fellow about a year ago in front of a convenience store -- this time, he was thumb-typing his cell-phone.

I had both of my vehicles serviced at my new repair shop this year. They have a veteran Isuzu mechanic who works there. Later, the service advisor -- Jeff -- e-mailed me about a customer he had who also had sticky valve lifters on his 96 Trooper. Told me the guy was deaf, and suggested I e-mail him about Marvel Mystery Oil. It was the same deaf guy, and we have an ongoing exchange now. I make a studied effort to treat my repair shop well, if they have consistently treated me the same way. I write good Yelp and Google reviews. I pass around business cards, and e-mail my local friends. I bring some bottles of Martinelli's before Christmas. It appears that I had brought them a customer before I had given them my business for the first time.

Then, Jeff himself decided to try MMO in his Chevy Suburban. Usually, people in repair shops are not all that keen about using chemical additives to "fix" their cars. But now, Jeff is doing it with MMO.

Here's this morning's conclusion, after I decided to warm up the Trooper for a bit when I went out for the newspaper. Each successive time I fired it up over the last few weeks, it ran better and better and the noise continued to attenuate. This morning, starting it cold, there was literally nothing of the valve noise you'd hear in any older vehicle starting cold.

At this point, I could change the oil at 2,000 miles. Should I add MMO again, or how much do I need to use? I never tried putting it in the fuel tank, but I may do that as well. At no time was there ever more than 24 oz of MMO in my crankcase -- less than the 20% of capacity they cite.

My Trooper is so important to me in its near-total restoration that I do oil changes at 1.5 to 2K miles because using a drain-valve is easy and clean. I could probably run a synthetic oil change after 10,000 miles, but I prefer keeping the car in fresh oil. I get the high-mileage XP filters, and may wait for 4,000 miles on the filter, although they're supposed to be good for 10,000.

 

[mindless1]

The first time you put goop in the oil to dissolve sludge, you do not want to leave it in for a long time, rather drain out all the sludge it has dissolved. If you don't do this, on an old vehicle there is a high chance it will clog up the oil filter then it starts bypassing and is ineffective at filtering the rest of the sludge now in suspension again.

Besides, MMO is probably just solvents in a higher viscosity oil, so once your sludge is dissolved, the solvents evaporate away and leave you with a higher viscosity oil, which you should be able to replicate by just using a higher viscosity oil on the next change.

In the fuel tank MMO will slowly foul your catalytic converter and O2 sensors, probably leave cylinders/plugs dirtier as well.

Next oil change, I would use no MMO, wait and see if the noise comes back. You can always add a little later.

 

[BonzaiDuck]

The first time you put goop in the oil to dissolve sludge, you do not want to leave it in for a long time, rather drain out all the sludge it has dissolved. If you don't do this, on an old vehicle there is a high chance it will clog up the oil filter then it starts bypassing and is ineffective at filtering the rest of the sludge now in suspension again.

Besides, MMO is probably just solvents in a higher viscosity oil, so once your sludge is dissolved, the solvents evaporate away and leave you with a higher viscosity oil, which you should be able to replicate by just using a higher viscosity oil on the next change.

In the fuel tank MMO will slowly foul your catalytic converter and O2 sensors, probably leave cylinders/plugs dirtier as well.

Next oil change, I would use no MMO, wait and see if the noise comes back. You can always add a little later.

That sounds reasonable. Other advisories suggest that old-car oil leaks are stifled by sludge buildup and that removing it will make for greater engine oil leaks. But I had treated the oil with Blue Devil Rear Main-Sealer, and the drop-pan shows about three or four drips over four weeks. I'm using one of those high-mileage Wix-XP oil filters. They're supposed to be good for 11,000 miles, but I'm going to change it out with the next oil change. Or maybe the one thereafter. I really think that I should do it this time, though.

I think the Trooper just needs to be driven more under reasonably sustained highway conditions. My HC-ppm was high this year, but the CO and NOx figures were the same. I bought some "Cata-Clean" but haven't used it yet -- or shouldn't have to unless I have a smog-test problem two years from now. The smog-test technician recommended it. Some opinions conclude that it doesn't do much for the cat-converter, but people swear by it for yielding better smog-test results.