Hg

Alright, I'm going to St. Louis, Missouri from Midwest City, Oklahoma for spring break. I'm thinking about doing this- changing oil just before I leave, going there for about a week, changing just before I come back, and then putting in synthetic when I get back. Ok, I've heard about some oils having cleaners in them or are a synthetic/natural blend, and that they should be used before switching to full synthetic. Is this true, and if so, what type of oil would you recomend I put in before I leave? Does this sound like a good plan or a waste of time and money? I just wanted to see what you guys thought, so don't flame me

KeithO

I had concerns about leaks in going to synthetic oil on my 88 IROC. At the time, it had about 91,000 miles on it. So, I went with the Mobil 1 with the red cap (5W-50, I believe) and I have had no leaks on 2,000 miles. I plan on moving to a thinner Mobil 1 for the next oil change. I am happy.

Caveat: "Your results may vary."

StangKiller

Don't worry about it, just change it to synthetic whenever you wan't too, they are compatable with each other.

SSC

This is an issue that's very debatable but a few of us do this when changing oil.
Its best to flush the oil before changing to synthetic, 5 min motor flush. This will reduce the amount of contamination when you do change to syn oil. If you go straight to synthetic expect your oil to be dark brown in about a week, synthetic oil contain detergent that reduces sludge and varnish but this contaminates the oil. If you flush the old oil it will reduce the chance of contamination. SO you might as well flush the dino juice and change to synthetic now before the trip this way you can take advantage of a better oil sooner and save some $$.

KeithO

Correction to above - I used Mobil 1 15W-50.

Also, that point about flushing is probably a good one. I didn't do this and probably should simply change the oil early to try to have a similar effect.

StangKiller

Be careful flushing your engine, a buddy of mine bought a used 87 Rustang GT, it ran perfect when he got it but he decided he wanted to flush the engine and then change to Mobil 1, he flushed it twice because all kind of gunk was coming out on the first flush, he refilled with Mobil 1 and within 100 miles his engine was knocking badly, we took it apart and discovered about 4" of sludge in the bottom of the oil pan and a stopped up pickup screen, and a badly scored crankshaft. The previous owner must not have changed the oil much so the engine flush broke loose all the crud and it all collected in the oil pan.

camaro6spd

sounds like the engine that came out of the '87 LOL that thing was ****ed up, number 8 cyl completey detroyed, con rod in 4 to 5 parts, piston sin uncountable parts, 2 stuck lifters that i can't get out so i just left them there, destroyed distributor gear, camshat all FUBARed......there was a 1/4" of sludge sitting atop the heads when i removed the valve covers, slutch coving the valve cover and lots more in the oil pan, and in the lifter valley.....Holy $hit was my first thought when i saw that.

SSC

This is true and can happen but many things can still happen reguardless.

1. Changed to synthetic oil and eventually all the crud would have lossened up and killed the engine anyway due to the cleansing effect of syn oil.
2. Not changed to syn oil and still the crud would build up and eventually prevent lubrication causing engine failure. Push rods and other oil passage ways plug very easily.

If you follow the instructions with motor flush, let the car reach operating temp, then add flush run for 5 minutes, remove oil filter and drain, repeat if needed with new oil and filter no harm usually comes to the engine. Of couse people could avoid sludge by not using Penzoil and changing thier oil in reccomended intervuals.



SSC

Hg

SSC: What is wrong with Penzoil anyway? I don't use that brand, but I'm just wondering. My friend recently bought a Civic and we put Mobile 1 Synthetic in(not trisynthetic, normal synthetic) and about 3 weeks to a month later weird $hit started happening... ended up replacing the engine. Sounded like a throw rod or something- a *BAD* knocking. His grandpa was a mechanic and was talking about penzoil guming up or something, and that if the previous owners used penzoil or didn't change the oil regularly, changing it and using good oil could've cleaned all the penzoil/gumup out. Can you give me the story behind this? Thanks.

SSC

My parents own a shop, I had worked for them for many years and I have torn down many engines and seen many different things.

Penzoil gunks up engines along with Quaker State and Havoline but thier not as bad. I did alot of engine jobs and just for kicks I would ask the people what type of oil they use. Most engines that I replaced were SBC and SBF (the easy jobs) the typical engine being replaced would have 140/200k miles on them. The people who used penzoil would have a the largest amounts of build up inside the engines it looked like black clay covering the lifter vally and valve train and the inside of the pans were covered in crust. The worst engine I tore into was a 4.3 out of a elcamino (120k with proof of regular penzoil oil changes) there was a good 1/2in of gunk covering the lifter valley. This el camino was in for a valve job, the machine shop had to hot tank the heads 3 times to get all of the buildup off. Usually the cleanest high milage engines used valvoline. Ive got nothing agaisnt Penzoil, Havoline or Quaker State, all oil does its job, but if you use these oils or any other for that matter flush the engine once a year for good measure.

johns84bird

Hmmm Wonder if the previous owner of my car used penzoil... when I changed the valvesprings at about 30k (newer crate motor) for the new cam, the part of the valve where it transitions from the stem to the flat part was caked with black ish that took forever to get off with a scraper and carb cleaner. Or does this mean bad gas?

five7kid

iTrader: (14)

The flush is a good idea. Plus, you might consider using one quart of synthetic, the rest petroleum in the change before you leave; flush & then 2 quarts synthetic, the rest petroleum in the change before you come back; then flush and a full synthetic change when you get back. Change the filter each time you do this.

The synthetic doesn't have more detergents "in" it, it has better detergent properties. But, the idea is the same, that deposits left by the petroleum-based lubes will be loosened and removed by the synthetic. The regimen I suggest above will help that to be a more gradual and thorough process than just changing directly to synthetic.

I have also observed the Pennzoil deposit effect. It was the worst with SF rated oils back in the '80's; they've "cleaned up" their act somewhat in the past couple of years. I still wouldn't recommend them, though.