90,000 miles in 17 or 18 years is well below average driving. I’m guessing the vehicle either sits quite a bit of the time or makes short trips. Either way, that type of driving could be tough on oil and on an engine.
How frequently do you change the oil? You probably need to change it by time intervals, rather than mileage.
I believe these engines had a propensity for developing sludge and therefore should have timely oil changes. Short trips and extended sitting can exacerbate the conditions. I’d opt for changing to and using full-synthetic oil if that is not what is being used.
Did the mechanic mention anything about crankcase pressure, blow-by, and/or PCV (positive crankcase ventilation) system? Next time in I’d have that checked and perhaps the PCV valve (if equipped).
Checking the oil regularly most of the time ("…I forgot to do it for 3 months…) is not the same as checking the oil regularly.
I get the shorthand now.
I know you guys understand this, but for the sake of the OP I thought an explanation might help him/her to understand how this works. So, in the interest of helping the OP better understand, here goes:
The entire space under the valve cover is pressurized by blowby that pressurizes the crankcase, and the pressure propagates up the paths through which the oil runs down into the crankcase after it lubes the camshafts. The oil pump basically squishes the oil out between the camshafts’ “sleeve” bearings and their respective wear surfaces, and the oil then runs out and into channels called “galleys” designed to direct it to return paths to flow it back into the oil pan. The galleys are on either side of the camshaft, and since the goal is to route the oil to the return paths, one side will always be lower. That’s the side where the oil will “puddle” and the pressure under the valve cover will tend to cause it to seep past a tired old valvecover gasket.
There is a device called a Positive Crankcase Ventilation (PCV) valve that allows a controlled amount of pressure to be relieved to the engine’s induction system bringing unwanted vapors with it to be burned by the engine. If this is clogged up with gump, excess pressure can build under the valve cover and exacerbate the seepage. It’d be a good idea to check the PCV valve. You can do so by removing it from the valvecover and shaking it. If it doesn’t rattle, it’s gumped up and needs to be cleaned or replaced. It’s part number 12204 in the attached drawing. Doing so isn’t in lieu of replacing the valvecover gasket and won’t totally solve the problem, but might reduce the seepage, and it should be done when the valvecover gasket is replaced anyway.
Why does the mechanic say 2 1/2 quarts of oil has been used then? Did you check it and it was ok, then the mechanic checked it sometime later and it was low ? In any event is sounds like the best course of action is to just let the shop replace the vavle cover gaskets. They can look inside that area with the valve covers off and see if they see anything else leaking at the same time. If this car has had it’s basic maintenance on schedule and driven conservatively, my guess is that the valve cover gasket replacement will probably be all you need. Suggest to not introduce the valve clearance issue at this time as long as there’s no drivability or performance problem. Keep it simple. The valve clearances can be checked later as part of an over-all tune-up. I check my Corolla’s valve clearances every couple years and just pop the valve cover back on w/the same gasket and a couple dabs of rtv, has always worked ok for me.
Ask your shop. When I do it I let the car sit overnight before driving it. Not so much by design, but b/c I do the job late in the day so no need to drive anywhere until the next day. B/c there’s that dab of RTV involved, it is probably better to let it set up overnight.
I checked the oil this morning and there is a little bit of white goop at the opening of the dipstick…I guess there is a little bit of gasket sealant inside the engine? Is that OK? Will it burn off?
White goop with consistency like a vanilla shake, or firm and rubbery?
If it’s liquid then it’s oil mixed with water.
Moisture can condense in the engine, either because of short trips that don’t fully warm up the engine, or the PCV valve isn’t doing its job.
Check under the oil fill cap for more “goop”.
While logical, the assumption isn’t correct. This type of goo doesn’t come down out of the drainplug with the used oil. It stays attached to parts upward of the normal oil flow, like the top of the fill tube and/or the bottom of the fill cap. It’s formed in the vapors of the crankcase and rises up with the vapors.
Clean it off and keep checking over the course of a month to see if the goop comes back. It might have been there all along and you just didn’t notice before.
I can’t imagine you’d lose over 2 quarts of oil even in 3 months through that valve cover gasket leak. These engines were known for oil consumption due to faulty piston rings - I had that problem with my 2002 Prizm, and it would be down 2 to 3 quarts between oil changes. That’s something you might want to look into before you run out of oil and wreck your engine.
You should not have allowed it to drop below the FILL line. Doing so exacerbates the problem.
Depending on the mileage on the engine, any useage less than one quart per 1,000 miles is considered by the manufacturer to be acceptable. One to two quarts between changes is perfectly normal and acceptable. You’re supposed to be checking it and adding a quart when the dipstick indicates.
That’s the valve cover and it looks like the “valve cover gasket” is shot. Replacement is cheap for parts but expensive for labor. You’d save a lot by doing it yourself. But the fact that you didn’t now what it was tells me you probably can’t. However, at least now that you know, a shady mechanic won’t be able to scam you that easily. (Got a really good mechanic that you want to date?) Actually, as long as your oil level doesn’t drop where your adding a quart every other day, you can ignore it for a while. Just keep an eye on the oil level. ALWAYS!!
