Rough Engine Idling/driving Issues - Corolland: the Toyota Corolla Forums

Ok, I drive a 1999 Toyota Corolla CE, to start out a few months ago my father changed my oil and left the oil cap off. I then proceded to drive the car around town on errand for approx 80 miles before I caught it. I freaked and immediately checked/ changed the oil again and it still had 3 of the 4 quarts left in it. The other quart was all over my engine.. About a month ago my car wouldn't start and I checked the spark plugs to find oil in the spark plug tubes. This led me to assume I needed a new gasket, I purchased a gasket and new plugs and a timing belt. My father and I installed it all and afterwards it started to run fine again.

Last week I tried to clean up the engine bay by washing it at the car wash, but I only used the car rinse setting, kept my distance and avoided the top of the engine from the spark plugs to the air filter. Then I started having issues again with the engine, now the check engine light flashes while I am driving and the car. I went to an autoshop and they said it was misfiring on all cylinders.. is that possible and it still runs? They told me to get a new coil. Not to be one to spend money immediately I wanted to see how you know a coil is bad. I checked online and a site said to ground each spark plug individually as someone cranks over the engine. The morning I tried that my car would not start. I then pulled the plugs to test the way described and they all sparked. To my dismay all the spark plugs had fuel and oil on the threads... I cleaned off each spark plug, tried starting it again and it weakly ran to life. I can figure out why there would be oil on the threads, I mean this is the part that is in the cylinder correct?

Since I tried to wash the engine, it's been a week, the engine now shakes the car at low rpms and sounds as if it is missfiring when I accelerate. I can barely reach 60 mph now and the car struggles to do this. When I stop for a stop sign I feel as if the car will shake apart. I read some of the posts on clogged sensors and have checked the MAF according to this post http://www.corolland...456#entry159456. I don't know if my issue is related to water from the washing last week or the oil on the spark plug threads. Any ideas for me to check or try would help, I don't have the money to run by toyota atm since I am about to pay for classes.

Thanks

Rush

** I just ran a compression test and got 120/110/90/90 Not good numbers but I can't seem to find the desired psi for the 1999 CE corolla does this mean I need a new head gasket or could it be something else?

Okay, I'm no experienced mechanic But I really hope that you covered the distributor cap with a bag or two tightly when you washed the engine- that will screw up the whole thing if you didn't cover it up. How many miles does this car have?

"Car engines that use a mechanical distributor may fail if they run into deep puddles because any water that leaks into the distributor can short out the electric current that should go through the spark plug, rerouting it directly to the body of the vehicle. This in turn causes the engine to stop as the fuel is not ignited in the cylinders. This problem can be fixed by removing the distributor's cap and drying the cap, cam, rotor and the contacts by: wiping with tissue paper or a clean rag, by blowing hot air on them, or using a moisture displacement spray ie. WD 40 or similar. Oil, dirt or other contaminants can cause similar problems, so the distributor should be kept clean inside and outside to ensure reliable operation." -Wikipedia

I don't think this corolla has a distributor cap. It has two coils that control two plug wires each. After compression testing I think I need a new head gasket at the least and to clean the valves off.

I also have a `99. It does not have a MAF. You could have residual oil in the spark plug tubes draining down to the spark plugs. Have you cleaned the plastic tubes inside and out along with the metal tube receptacles above the spark plugs, then monitored to see if oil reappears? If oil reappears around the bottom edge of the plastic tube(s) or around the base of the installed spark plug(s), I would try a new gasket again. Be sure to soak up as much oil as possible before removing the spark plugs.

I just replaced the valve cover gasket, but the performance hasn't changed. Is there any way I can test the coils and spark plug cables? I have an ohm meter, but people keep telling me that won't work with the cables. If the resistance is high, then that would mean that the cables have corroded, right?

So far, my options are to buy and install non-returnable coils and see if they work, go through the effort of replacing the head gasket, or buying a new engine or car. I don't have the money to buy a new car and blowing more money on parts I don't need doesn't seem too attractive. The main issue that I've heard about the compression test I did is that I did it wrong. I installed the sensor into each of the spark plug sockets, one by one, took out the fuel pump fuse to keep it from spraying fuel, and cranked the engine,by key, until I got a max reading. They read, from one to four, 120psi, 110psi, 90psi, and 90psi. My friend told me that it was most likely a failed head gasket. I think this is possible if you think about expanding and compressing cold water has on a hot engine like when I washed it, but then again, this would have happened in the winter too.

What are some diagnostic tests I can do in order to find out what it is specifically and how can I test the coils and cables?

Hard to get a definite answer from a multimeter reading, as sparkplug wires are more than just a conductor. Depending on what plug wires are on the car, you could see ranges in the Kilohms or even Megohms. If they are spiral core (most are nowadays a hybrid of low resistance spiral cores and high resistance carbon cores for performance and RFI/EMI rejection) - then you need to pulse a high energy AC signal down to test the cable, as you need to pickup current from the induced magnetic field.

But checking the resistance with a good multimeter is good practice anyways - you can find open cables (infinite resistance) and cables that are too low in resistance (damaged core, short to another conductor). The plug wires should all be roughly the same in resistance, any one that is grossly dissimilar is likely to be the bad cable. Same with the coils - you can check the resistance of the primary and secondary coils, should be similar for the two coils. Measure resistance of the coils when cold and when hot - as they will be slightly different. If I remember correctly - the plug wires should read in the 10K-30K Ohms and primary coil is under an Ohm, secondary coil is hundreds to thousands of Ohms. Resistance should increase as they get hotter.

As for compression testing - the engine should be warmed up prior to testing, to make sure clearances are correct. You method is fine for measuring the compression, just make sure each connection is as tight as possible (no pressure escaping past the threads of the compression tester). Also redo the compression test after hitting each cylinder with a squirt of motor oil, and see if the compression changes or not. Difference of 120PSI to 90PSI is pretty bad, but not bad enough to say that there is definitely a bad headgasket. Don't confuse low compression with a failed gasket, could be as simple as a worn valve or leaky rings (hence adding a squirt of oil and retesting). If compression goes up markedly, likely worn rings. If it doesn't change - could be valve seals or bad a valve or stuck valve(s). If you got very low pressures (pressures in the teens), then only then I would start to suspect a bad headgasket. The spec'd range for compression on the 1ZZ-FE is 218PSI-145PSI with no more than 15PSI difference between cylinders.

Washing an engine is always risky - especially if you shock a hot aluminum engine with cold water. But from your description - sounds more like water seeping in-between connectors. Try running the engine at idle for a little while, 10-15 minutes to get everything warmed up and drive off any moisture. At the very least, check the plug wires and sparkplugs themselves for being wet/corroded ends. Look down each plug well before you remove the plug, if there is water or fluid pooled there, do NOT remove the plug until you dry that up first. Otherwise that will just drop onto the top of piston and you might end up with another problem on your hand to deal with. If possible, pickup another set of fresh plugs. Install them, run the car, note how it runs. Let the engine cool and remove the plugs and "read" the ends. Noting anything grossly different from one plug to another and noting which cylinder each sparkplug came out of. Reinstall them and drive around normally (or as much as you can), remove them after a few hundred miles and "read" the ends again, noting if there are any changes compared to previous time you read the plugs.

You original post mentioned a "timing belt", I'm hoping you meant a serpentine belt or accessory belt, as this generation of Corolla uses a timing chain. And as mentioned above - your model year does not have a MAF sensor, it is MAP based. You do not have a distributor, but two coil packs and a set of high tension sparkplug wires.

I've washed a few engines in the past and the first one I did made me oh-so-careful afterwards. I ended up with a similar situation with rough running/idling and the cure was replacing the coil/distributor and wires. Apparently the wires had soaked up enough water to cause arcing and misfiring and messed up my ignition system pretty bad. I was lucky enough to find a donor vehicle at the junkyard.

I agree with fishexpo101 - a headgasket would likely not cause the rough running. As suggested it's likely coil pack/wires. If possible I'd check a local junkyard for a donor. I'd imagine it would be pretty cheap for that vintage.

Today, I re-tested the compression. This time, I took all the spark plugs out so it read much higher, the highest being 215. The other three all read 190. This is good news, considering it is not a compression issue. One thing I did notice was that three of the four spark plugs looked very blackened at the ends, while the other looked new. They are all new, and the clean one was from the cylinder with the highest compression reading. Why is it the spark plugs would look fouled? Then I decided to test the plug wires, using a multimeter, all of which read equal numbers. After this I removed the coil packs, examining for cracks or breaks. Neither of the coil packs appeared damaged so I reinstalled them. Now I am out of possibilities. I will try to replace the coil packs, seeing if this will clear up any misfiring. Does anyone have any other clues as to my problems?

If you are running the original spark plug wires, I would replace them before I'd replace the coil. An old trick is to run the car, with the hood up at night or inside a garage (not for too long, don't want to run into asphyxia). Note any arcing between the components under the hood - look carefully, it will be quite dim and hard to see.

From your description - sounds like at three of the plugs are carbon fouled. Most likely cause is misfires, from either a weak spark (faulty coil), bad plug wires, or an incorrect gap on spark plugs.

MkII_5SFE

These problems with fouled plugs mostly arise from rich a/f mixtures and possibly oil in the intake from your breather tube. (most connect to the intake itself) as crankcase pressure builds from regular engine wear, some oil vapor, along with fuel and water, end up in the intake, and get burnt off.

Now for it to build up that fast?

I would check all emission components.

Possibly your O2 sensors/afm those sorts of things.

Give your engine a complete tune up (to include air filter and ignition cables) if it has a distributor, replace cap and rotor.

I would also take off your air intake at the throttle body and look inside for carbon/oil buildup and residue.

Use carb cleaner to soften and remove built up nasty.

To get the stubborn crap, get a nylon bristle brush used for auto hobby cleaning/detailing (usually sold with a brass and steel wire brush as well)

dont use any metals as if the bristles fall off, the metal can do more damage than nylon.

Always be careful when working with intake components as if you drop FOD (foreign object debris) you can end up with a severely fried engine.

Also check your pcv valve(s) and vaccum lines for clogs and whatnot.

Good luck in your endeavor.

I'm no mechanic either but my Corolla (2000) has had oil on the spark plug threads since I bought it. It has 123,000 now (had 111,000 when I bought it), and has had NO driveability issues due to the oil.

99 corolla suddenly started missing

I first dried out water in spark plug holes 1 and 2 with rag and screwdriver and it ran a lot better but wasn't right.

Solution for me was also simply disconnecting, wiping down and reconnecting plug wires at the coil.

Always look for the simple fix and always disconnect and reconnect contacts on an item before replacing it