A method to install most gaskets
Dear Mike: Can I put gasket sealer on the rubber gasket on my oil pan? I’ve spent an entire afternoon trying to reinstall it after changing the rear main seal. I always manage to drop the thing or to lose the end in the pan while balancing the whole mess on my hand as I try to start the bolts.
The gasket instructions said not to use any sealer. I’ve gotten the thing on at least twice, but had to remove it to keep from cross-threading the last few bolts, apparently because the gasket was pinched somewhere.
I need three more hands, and there’s no room under my car for a helper.
— T.F., Mobile, Ala.
A: Used to be that you could use a shellac-based gasket sealer to glue the cork gasket to an oil or transmission pan or valve cover. But now many gaskets are engineered from rubber and elastomers, and using any sealing compound is more likely, not less likely, to make them leak. They are designed to be used dry.
•Here’s a general scheme for installing any gasket, even a cork one, that’s large or complex. First use a rag to clean the gasket surface of the block or trans housing and the pan, and be sure that there is no residue of the old gasket or dirt left behind. Use carb cleaner, mineral spirits or lacquer thinner if you’ve got some stubborn deposits. Don’t scrape with anything more substantial than a credit card, though, or you may leave scratches which may leak.
•Get several studs, 3 inches long or so, in the same thread as the pan bolts. If you have to, simply hacksaw the heads off some bolts and deburr them. I keep these in my toolbox for the next time. Thread the studs into the corners of the block or trans case, a half-dozen or so turns.
•Next you can position the gasket on the studs, close to the block. The threads on the studs will keep the gasket from falling back onto your face. Now you can lift the pan up and start the other pan bolts by hand.
•Warning: Don’t run any of the pan bolts in more than three turns until they are all started. That’s probably the source of your problem with cross-threading. If even one of the bolts is turned down hand-tight against the pan, it will anchor the pan and the last few bolts won’t thread in straight, because the holes in the pan won’t line up with the holes in the block. Keep wiggling the pan around as you thread in more bolts.
•When the rest of the bolts are in, you can unthread the studs and replace them with the remaining bolts. Tighten the bolts in a crisscross pattern, not a circular one, and tighten three times — once fingertight, once to half the torque spec and once to full torque.
Dear Mike: I live in Minnesota, where we have E85 fuel (made with 85 percent ethanol) available. When gas prices rose over $2 a gallon, there was a news story about people buying E85 because it was only $1.50 a gallon. The news report said that everyone should be careful because E85 could cause damage to the engine.
I checked the owner’s manuals for both our cars — a 2002 Plymouth Grand Voyager and a 2004 Chevy Cavalier. The manuals recommend regular 87-octane fuel, but state that these cars can use some ethanol-based fuel.
Now that fuel prices are even higher, I’m interested in using E85. Can I do that without causing problems?
— P.H., Monticello, Minn.
A: No, you can’t. I predict a great many damaged fuel systems in areas where E85 is for sale.
It is suitable only for “flexible-fuel” cars — cars that have been engineered to use it. The owner’s manual will make it clear if you have a flexible-fuel vehicle. Using E85 in a vehicle not specifically labeled as flexible-fuel will damage it in short order.
Conventional cars and trucks cannot use E85 because it is corrosive, and will damage almost every wetted part of the fuel system that it touches. Dual-fuel vehicles have stainless-steel fuel tanks and upgraded seals, fuel injectors and other parts.
In addition, E85 provides less energy per gallon than gasoline. Dual-fuel vehicles have a sensor in the system to change the quantity of fuel injected and to modify the ignition timing to compensate. They also use an injector capable of higher injection volume. A conventional vehicle running on E85 will run poorly, with reduced performance and mileage, and may also suffer engine damage from running too lean.
Because of the lessened energy content and the reduced mileage, you may not realize any actual savings by using E85. If you’re paying $1.50 per gallon for E85 instead of $2 for 87-octane unleaded regular, and if you get only 12 mpg instead of 19 mpg, you’re behind the money-per-mile curve. Dual-fuel vehicles will achieve a better cost-per-mile ratio.
Chrysler suggests no more than a total of 10-percent concentration of oxygen-carrying compounds such as ethanol, MTBE, ETBE or MMT, and limits the methanol content to 3 percent or less. Other car manufacturers have similar prohibitions.
Dear Mike: I have a 1997 Buick LeSabre. Recently, as I switched on the ignition, I heard a very loud pop and smoke came from under the hood. When the smoke cleared I opened the hood, and the top of the engine was in shambles. The mechanic who replaced the intake manifold and several other damaged parts said that he had never seen anything like it.
How can this happen?
— R.S., Sparta, Ga.
A: A backfire caused a small explosion, and the plastic intake manifold went up like a grenade.
GM has a recall on this — it’s 97-C-02 — and will replace the manifold and reflash the engine’s computer to prevent more backfires. You apparently didn’t get the recall letter.