I'm debating on whether or not to switch to synthetic in my TPI 305. It's got 160K miles on it. I've heard of problems with synthetic before, and my friend switched to synthetic in his car(not a 3rd gen) and it cleaned out a bunch of crap, but it also got real low on oil and ended up messing up a bearing. BUT I know for a fact he drove it really hard too. Someone said to switch to synthetic, but change the oil and filter after 1500 instead of 3000 miles. Just wondering what your thoughts were on this.

 

Quicksilver,

How clean do you think your engine is, internally? If it is relatively clean, you shouldn't have any problems. If you have a lot of buildup, you could be causing some headaches. If there is any external leakage, it will only get worse with synthetics. If everything is in good condition, go for it.

How regular has the maintenance been? If you have been changing oil at the specified intervals, the engine should already be fairly clean, regardless of mileage. The synthetic will only protect and lubricate better, and continue to clean up the engine in that case. If the oil changes have been neglected, you might want to work your way up to synthetic by starting with a blend or high-mileage formulation.

 

Quicksilver??

 

Hmmm from Vaders comments, I would say its better to be safe than sorry. I got 108k miles, I was also thinking of getting synthetic... maybe not?? They say you have to change it at 1500 miles, due to the fact that synthetic will loosen the build up, thus clogging the oil filter, and well if you're gonna change the filter, change the oil also (which probably now has some build up in it). I'm skeptical now to it, maybe I'll try a blend and work my way up to synthetic like Vader said.

 

Vader: Just how did you find out what Hg stood for? Anyway... I got this '87 Z28, stock LB9 back in August or so. Doesn't get driven much seeing as I don't have a license yet. Done a full tune up, oil(dad gets superflo by the cases so that's what went in), fram filter(I learned from a gearhead at pep boys the err of my ways here), fuel filter, K&N's, tranny fluid, new coil, cap, rotor, wires, harness had to be replaced(it was fubar and took out 2 coils, not sure WHICH harness it was though... there is more than one, isn't there?), plugs(delco all the way), new fuel pump and sending unit, gas tank was cleaned out, and radiator flush. Put in some of that Redline water wetter also. There's only a SLIGHT oil leak. It leaves no more than the size of your palm(if you have medium size hands), and this has built up since that August. Nothing you wouldn't see on a normal car, hell, our '99 Sebring leaks slightly, but the oil filter may not be as tight as it should be. The last guy *SAID* he changed the oil and filter regularly, but no telling if he was BS-ing and how people treated it before him. I think it's at least been partially rebuilt or else cleaned out cause he said someone put sugar in the tank. What kind of blends are there? And how are high mileage formula's any different than normal? Are they made different or something?

 

Hg (periodic symbol for elemental mercury) is also known as quicksilver in some circles. A clever username, especially if "Hg" has a silver 'F' car, wouldn't you say?

 

Either that or he has some POS Mercury Sable.

 

Actually, I cheated and used "The Force"...

 

Well, close. He does share a driveway with a leaky Sebring... (Was that a little redundant?)

Just jerking your chain a little, Hg!

As for the cleanliness of the engine, you really can't tell what conditions you might have if you don't have a complete history, unless you want to remove the rocker covers and take a closer look. Since that's usually the hottest part of the engine, varnish will appear there first. If you have deposits there, you probably have them everywhere. A thin tan coating is just fine, but thick deposits are certainly a problem. You might even get a good enough look through the oil filler cap to see what's going on.

There are a few other things that you mentioned that are of interest, though. As for cleaning out the fuel system, it has very little to do with the deposits in the crankcase. What's even more interesting is that only very little refined sugar will dissolve in gasoline or alcohol before the liquid is saturated. If it managed to get through the pump in granular form, the filter would have caught it an likely plugged. Sugar in the gas tank sounds like a real problem, but doesn't do what many people think it will. If I were that P.O.ed at someone, I'd find something a lot better than sugar.

Another thing you can do to improve your reliability is to use anything but an Allied Signal/Fram oil filter. Wix, AC/Delco, Purolator, and even some Bosch filters are far better than Fram filters. Even Chrysler doesn't use them from the factory any more - that's how poor the quality can be. They use fewer square inches of filter paper than almost anyone, use paper drainback valves instead of silicone rubber, and have marginally thin shells and heads that may blow out under pressure. Aside from that, they're just great.

Another key in keeping the engine clean is a functioning PCV system. Make sure the hoses are intact and the PCV valve is clean and working.

And now to the oil. It is far more important to use the correct viscosity oil and change it regularly. Your 1987 car is not a Mitsubishi/Chrysler Sebring, and was not really engineered with clearances suitable for a 0W- or 5W-anything oil. If you are using mineral oils, your car requires 15W-40 or 20W-40 above 20°F or SAE 30 above 40°F. You can use 5W-30 up to 60°F air temperature, but not beyond. At least that's what your 1987 owners manual should read, and the people who wrote that also built your engine. Newer engines are designed for lower viscosity oils, but not your engine.

And be careful when considering viscosity numbers. The numeric ranges of CC²/sec (centistokes) for a given SAE viscosity index are so non-linear and have such different meanings for gear oils and crankcase oils, hot versus cold ratings, that the scale is a bit misleading, to say the least. Too bad the Society hasn't caught up with the 1980's yet.

This link might make that a little more evident:
http://www.escape.ca/~dbrad/viscosity_c.htm

In the mean time, it's up to you to protect your assets, so don't rely on a 5W mineral oil for much more than an easy cold start. They don't provide much more than minimal protection at higher operating temperatures for more than a couple thousand miles, and begin breaking down quickly at higher temperatures.

Concerning the oils designed for cleaning older engines, Quaker State has a relatively new product that lubricates well, has reportedly good viscosity stability (for a mineral oil), and extra cleaners and seal conditioners specifically for older engines. If you have a small leak, it may get worse as the engine cleans itself, or it may get better. Obviously, larger leaks won't be helped by any oil, but yours sounds like a small leak. Between snugging up the oil pan bolts and valve covers, cleaning the outside of the engine thoroughly, and using a conditioning oil, you might be able to determine where the leak is and eliminate it. The seal conditioning alone may help.

As for your oil, the Exxon SuperFlo is essentially the same as Mobil 0. You DO know that Exxon-Mobil is one company, right? Mobil does most of the synthesizing and blending, and serves the automotive lubrication and industrial synthetics markets. Exxon controls most of the procurement and commodity marketing of mineral oils. Exxon engine oil = Mobil engine oil (for the sake of argument).

Just like Exxon/Mobil, Pennzoil and Quaker State are one company. The base stocks are mostly controlled by Pennzoil, and Quaker State does most of the blending and marketing for the automotive segment. In essence, Pennzoil = Quaker State, in a different bottle.

Just as important, your engine also requires an oil change every 3,000 miles. Read the manual carefully and you'll see that, too. Mineral oils break down pretty quickly, and the additives that improve them break down even faster. After 3,000 miles, you really don't have much viscosity stability with multi grade mineral oils, and the additives are just about spent and begin burning up. The contaminants they produce will wipe out any cleaning they may have done if you don't change it regularly - the oil becomes it's own worst enemy.

Synthetics are a different matter entirely. They maintain viscosity across such a large temperature range that the SAE viscosity rating system is all but rendered completely meaningless with synthetics. The viscosity of most good PAO crankcase oils changes even less than that of water over a similar temperature range. They are naturally "multi grade" oils by the antiquated SAE viscosity scales, so they really require no fortifiers to maintain viscosity. The lack of fortifiers and viscosity improvers means there are fewer particles to break down and burn as the oil gets older, so there is almost no ash and soot created by synthetics as is common with mineral oils.

Synthetics probably clean better than anything, but are also more expensive. Synthetic blends are a viable choice for your application, at least after you can determine if the leaks are under control and the sludge is getting filtered out instead of circulating in the engine - another good reason to use a better filter. Once the engine is sealed, synthetic blends and regular changes will start cleaning up the varnish and sludge. Once you are pretty secure in that, full synthetic should be safe. Pure synthetic lubes are the best for protection, lubrication under all conditions, and prevention of deposits. I have several older, high-mileage engines running on full synthetic with no problems, as long as you don't consider the cost as a problem.

Remember that the key will be the correct viscosity and regular changes, not necessarily the kind of lubricant base stock. It is far better to change mineral oil regularly than to stretch the change intervals on synthetics.

 

That's EXACTLY what I use Hg for, Quiksilver. Anyway... My dad, who knows a WHOLE lot more than me, said the leak is the front and rear main oil seals. I guess that's what they're called... the seals around the crank shaft in the front and back. I've got new valve covers, but I still need to get new gaskets, so I take it this would be a good time to see how she looks inside? My oilcap says 5W-30 and the manual says "An SF/CC quality, SAE 5W-30, Energy-Conserving oil is the preferred engine oil for your vehicle." The guy at pep boys told me that when he used to work at O'Reilleys around New Years, it was REALLY slow, so they went back and grabbed a bunch of oil filters from cars they'd changed oil and ripped 'em open. The Fram was crappy inside, but the purolators, Wix, and others were good. He thought it coulda just been that one fram, like a certain model ya know? So he went and grabbed a different model number and it was the same. He did this to like 4 or 5 models with the same results. I'm gonna get that metallic blue Purolator from now on, he said it was a good one.

 

Hg,

I understand what the oil filler cap says. Mine says the same thing. The owners manual also states "5W-30", but you need to read the entire section in the manual about engine lubrication to see the temperature at which you can safely use that viscosity oil. If you are using a synthetic rated SAE 5W-30, it isn't an issue. But mineral oils rated 5W-30 are a real risk at higher operating temperatures. The 5W-30 is great for corporate fuel economy averages, which is likely why the cap is labelled so. It's not that good for engine protection, however. 5W-30 begins to vaporize and create ash at higher temperatures, more readily than higher viscosity oils.

If you do decide to use 5W-30 mineral oil for whatever reason, you need to change it a 3,000 mile intervals or less, and do it religiously. Three months in the sump is about all that's good for.

It sounds like the guy at Pep Boys discovered the same thing everyone else has. Grab some AC/Delco filters, or something comparable. The Puros are pretty good as well, or at least better than the Fram standard line. The Fram X-tra Guards might be a little better, but are certainly suspect since the regular line is so poor. These are from the same company that makes Autolite ignition parts, and you really won't hear a lot of people raving about those either.

And your father is likely correct. End seals seem to be the first to go. Fortunately, if they are only sludged and not damaged, you may be able to "revive" them with the seal conditioners in some engine oils. If not, you'll at least be sure that the leakage isn't due to sludge and contamination. Since the front seal is extremely close to the lower oil pan extension, examine that area closely to make sure all the leakage is from the seal. There may be some leakage from the pan lip contributing to the mess, and that may be helped by lightly snugging the oil pan bolts. At least when you get under there an take a good look, you'll see exactly what he is telling you about the seal leakage. The front seal isn't that difficult to change, but is time consuming. The rear main seal is a different matter entirely.

 

Lol, yeah, he told me what was involved in changing the rear seal. Iiiiiiiiii'm not doing that myself.

 

socal climate=Valvoline 20-50 conventional. colder ambients-slightly thinner. that 5w-30 isnt suitable for any use other than helping produce cafe numbers that the corporate spin doctors can spew out to a concerned john q. citizen. some newer motors are set up differently especially in areas where machined tolerances are concerned, and those motors need the lighter oil, no question there. but our cars especially v8 20-50 is it. if you have 160k on the tpi motor and you are debating about a switch to synthetic, stick with conventional till rebuild time, once broken in start there with synthetic, if the oil isnt leaking alot now, it will be soon enough after switching. best bet -if you were to walk into my shop, and ask, that is-would be check on blowby first-unscrew oil filler cap, then a) add flourescent dye b)drive car 100 miles c)black light engine and pinpoint leaks d)depending on how many leaks are present-start pecking away at the leaks usually starting with the leak highest up on the motor-v.covers. and as time/customer budget allows, repair the rest. e) a/c delco pcv valve. f) stress regular oil changes-finally and it took almost everything i got to hold it in cuz i type slower than the second coming PENNZIOL-QUAKER STATE AHHHHHH SHEEEEEIT RUN AWAY:lala:

 

So what would you guys recomend for Oklahoma? I'm in Midwest City, which is pretty much Oklahoma City. We see from the 20 degree range all the way up to around 110 degrees.

 

How come it took so many fewer words for you to say the same thing? Man, I must be slower than your typing.


I've done that on AC systems, but never heard of it for engine oil. Do you use the same dye since it will mix with oil? Pretty clever...


Sounds like you you may have read about my experience with aftermarket PCVs, or encountered the same problems too. I hated to bring that up, since I'd already slammed Fram enough over their inferior filters.


AMEN! Neglecting that has to be among the worst maintenance mistakes people can make.


Glad you could hold it! My monitor couldn't take the liquid.

 

Didn't read all the posts, shoot me if this has already been said. There is a lot of cool stuff you can play around with with synthetic oil. Temerature is the biggest thing. With an oil cooler and some time, you can play round with hot oil and block temerature. Pumping up the heat, you can gain some et, as much as 2 tenths. This is a great braket racing tip, that way you can pump up the heat and run closer to your dial in when the air is crappy. You can also run it cool and get great gas milage. Funny stuff!!!

 

that would be the second coming of j. chr-st-you silly ninnie. but *** to think of it i am gettin older-nah

 

GGA,

I was pretty sure I knew what you were talking about the first time. Coffee does have its down-side, but something has to keep us going. I didn't get the other reference to what you were saying until I read it again - I must be getting slow... DOH!

 

About the PCV valve, what happens if you use an aftermarket one vs. an AC part out of curiosity?

 

My apologies to all that have read this before, but it IS a legitimate question.

The PCV valve is in essence a "programmed" vacuum leak. The rate of air flow through the valve is controlled by the shape of the pintle, the shape of the housing, and the calibration of both of the springs. At any given intake vacuum level, the valve pintle will either open or close on one end or the other, regulating the amount of air flow through the valve. A slight variance in air flow in the PCV system can make a large difference in the manifold vacuum and thus the operation of the engine, especially one that relies on a MAP input for fuel calculations. It is critical that the PCV flows at the correct rates under all operating conditions so that the ECM programming can regulate fuel properly based on the presumed amount of PCV air. Too much or too little PCV air will skew the mixture either lean or rich, causing the ECM to vary away from its ideal mixture control parameters. In open-loop mode and at idle, this can really cause problems since the oxygen sensor feedback may be ignored.

I used to work for a company that forged the pintles for Robertshaw (OEM and aftermarket supplier of many automotive components). The pintles were tested after manufacture with a calibrated spring on a flow test bench. The allowable variation was less than 0.5 l/min. That may sound like a lot, but it really isn't when you consider the fluid is air, not liquid. That may seem like excessive testing, but it assures the proper flow despite any dimensional measurements. And there is a good reason for the testing.

I had one EFI vehicle that would not idle correctly after performing some routine maintenance. After new plugs, wires, cap, rotor, filters, fluids, clean IAC, reset TPS, replacement IAC, cleaned EGR, repalcement gaskets, new hoses everywhere, and about a week of frustration, I speculated that the vacuum leak that was causing the high idle was from the PCV. I dug the old AC/Delco PCV valve out of the trash and cleaned and reinstalled it. Everything immediately returned to normal. The supposedly OEM replacement PCV valve from Allied Signal/Fram was obviously NOT calibrated to the engine. I double checked the application numbers, and it was the correct part number specified for the engine. Either the part was mis-labelled, or the flow calibration wasn't even close. In either case, I realized that there were some serious quality-control problems at Fram, at least in my experience. Because of that, I also realized just how important a correct PCV is to the proper operation of the system.

From that, I also decided not to risk saving a few bucks on aftermarket parts, but insist on the genuine article for my vehicles. That doesn't mean there aren't good aftermarket parts to be had, but if GM is putting their name on the package its a good indication that you have the right part for the application. If not, you should at least have a reputable company standing behind the parts. If you do some research and discover who supplies GM with some of their parts, you can save a few bucks by using their aftermarket, but often it just isn't worth the time.

Just thought I'd share that with you one more time.