1990 Ford Tempo

here we go again. I have a 1990 Ford Tempo and the check engine light periodically goes on and off. It seems to happen most after being driven on the highway for 20 - 30 minutes. It idles a little rough, but has done so for awhile. Someone has mentioned that it could be the vacuum seals or something like that, but I have no idea where they are. With regards to the current problem. It does not stall when it is in drive and you stop, but when you put it in park it does. Again usually after the check engine light is either on or has gone on and then turned off. Any suggestions would be helpful, not to mention pointing out the vacuum seals? I am trying to keep this car running for my fiance while she is in school. Thanks.

I suspect that someone was either trying to tell you that your valve seals were leaking causing your oil pressure problem (oil light rather than CEL?) or that you have a vacuum leak causing your car to stall when you put it in park. Both thoughts seem logical and neither is correct.

Valve seals leaking cause oil to be drawn into the cylinders during startup and deceleration. The do not cause pressure drops in an operating engine. And they do not cause the CEL to go on and off.

And, since this is a 1990, I have to ask you…are you really alluding to the oil light or possibly even the battery light rather than a check engine light??? Could you clarify please?

A vacuum leak can cause rough idling, but it also causes rough accelerating and operation overall.

How many miles does the car have on it? When was the last time it had a thorough tuneup?

First, I suspect lack of a tune up is causing misfire. You could start down the tune up list: 1.spark plugs; 2.spark plug wires; 3. distributor cap and rotor; 4. air filter; 5. pcv valve; 6. fuel filter. that’s a start. You can get a code scanner (actually, it’s a code reader) for $29.95 for that Ford with OBD 1 emissions systems. I think it will show misfire code(s). Let us know.

Well, you are driving something that shouldn’t still be on any road if it needs $50 worth of repair work. Get rid of it before somebody gets hurt. Explore other options. Everybody has parents and uncles and aunts. Hit them up for some assistance. The throttle position sensors are sometimes the culprit on Tempos. I had to replace mine twice as the ones for the tempo are trash. Your check engine light could indicate low oil pressure. Does it say check engine or does it just say engine? If it only says engine, I would change the oil pressure sensor near the distributor. I do believe it is the check engine light so did I mention scrapping the Tempo? Some people think I’m only joking but the Tempo has other problems that are really surprising and clean the battery terminals. Good luck.

I am almost positive that is is a ‘check engine light’. the car has 118,000 miles (most grandma miles)the last time it had a major tune-up was less than a year ago. I have never seen an ‘oil light’ kick on. I do know that it has an ‘amp light’. I have only recently started driving this full time as my ancient car (1990 New Yorker) bit the dust in October.

My finance just informed me that it is a ‘service engine soon’ light, not ‘check engine’

“Tune up” and “major tune up” have no standard definition. Unless specified, they can be just buzz words. That’s why I listed what I thought would make a decent “tune up” …parts-wise. Even if the spark plugs were changed in the last year, they could still be fouled by an oil leak (or, worse, anti-freeze leak),now. Pull the spark plugs and examine them. If some of them are fouled, replace those.

You are dealing with an 18 year old car–almost old enough to be in college. It would be good to have a trusted independent mechanic check to be certain that it is safe (no serious rust-out of the chassis, no excessive looseness in the steering gear, no major suspension problems. If it passes this test, then find out what the engine needs. If the car is safe to drive, some careful driving may just make the car last while your fiance is in school.

Please note that bad valve seals will not cause low oil pressure unless they cause enough oil consumption to use up most of your oil. Once your oil pump can no longer pick up oil from the oil pan, you will have low oil pressure. By that time, you’ve already done damage to your engine.

Start with new plugs and check the plug wires with an ohmmeter. They should have 5000 to 15000 ohms as a general rule. If one or more test completely open, (infinite ohms) replace them.