Low Compression Misfiring 2013 Corolla, need it to last 9 more months, HELP!

2013 Corolla 218k miles. Low compression on all cylinders (60-70 on each one). Misfiring in cylinders 2 and 4 according to OBD2. Dealer quoted me ~3500 for new engine, said there’s scarring on all the cylinders particularly #2. Trying to nurse it for 9 more months if possible. I’m about to finish medical school and would love to be able to get another 9 months out of it and buy a new car when I start residency in June/July. If not I’m just going to put that 3500 toward a new car and just do it that way.

I swapped coils to check for issues with them, no dice, the misfire doesn’t follow the coils. I haven’t gotten down to the spark plugs yet but that’s my next step. If y’all know anything to help me get to next July I’d be thankful! Or if you think I’d just be better off putting that money toward a new car now let me know too.

Thanks y’all!

I’m also a Corolla owner & that’s what I’d do were I in that situation. 218K miles on the original engine, and I’m guessing not an overzealous approach to the maintenance, pretty good.

Just buy a few plugs and replace #2 as needed. On your next car though change oil more often

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I’ve changed the oil every 5k religiously. I know the scarring suggests otherwise but I swear I’ve never gone more than 6k without an oil change. Walmart cracked the oil filter cap and apparently it leaked and I think that’s what did it

oil changes every 5k religiously. one walmart trip where they cracked my oil filter cap but that was 4 years ago. any idea why the issues would pop up now?

A can of Restore Engine Treatment wouldn’t hurt, follow the directions.

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5k oil and filter changes are what I use, & I have over 200K w/ no engine problems. So that isn’t the cause. I’m guessing the oil leak caused the engine oil to get too low between changes at some point. That will definitely damage an engine quickly,& more or less unrelated to the oil change interval. Did the low oil pressure dashboard warning light ever turn on? Cooling system & EGR problems are other possible culprits. I’d recommend however to just feel lucky you got over 200k on your trusty Corolla. You’re already ahead of the game!

nah no warning lights or anything came on ever. In fact the only reason I know it happened was I was driving home one night and the engine sounded weird so I pulled over and checked the oil level and there was none in there. I had some oil in my trunk, topped it off and drove it straight over to the dealership where they informed me of the problem

How long have you owned it? A previous owner may have abused the car and caused the engine problems.

I’m a little curious here. If the dealer did a compression test and used a borescope on those cylinders, why didn’t he at least suggest new plugs while they were out? He could not tell if the cylinders were scored unless he used a borescope camera and cannot do a compression test without removing the plugs. How much did he charge to do all this?

You stated

But the OBD says there is a misfire on cylinders #2 and #4. If there was a misfire, the check engine light would have come on.

If it were me, I’d do an oil change and if I had someone else do it, I’d check the dipstick to make sure it was done. Also look at the oil filter and if it doesn’t look new, there would be words. And I’d replace all the plugs.

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When I write an estimate to replace a failed engine, I’m not going to install new spark plugs in the old engine.

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That’s pretty much dead engine & misfire territory. Why misfire only on 2/4? IDK. The misfire counts are probably similar if the 60-70 is accurate. Who did the compression test? The stealership?

As @texases mentioned, since it’s FUBAR, you could try a can of Restore (following the directions, as mentioned). It’s a band aid on an amputation, but it’s not that expensive and can’t hurt anything more than it’s hurt. It might limp it along.

Alternatively, if you found a local, independent shop with a decent rep I’ll bet you could get a used, junkyard engine dropped into if for something like 1/2 of the dealer quote. Still a kick in the pants if you’re trying to finish med school, but if the rest of the car is ok, it might be an easier pill to swallow than buying some other cheap devil that you don’t know.

If you go that route, make sure they give it a new rear main and trans pump seals while they’re at it.

You missed my point.

If all cylinders are low compression, then it could be the timing chain slipped a tooth.

I have no idea why you thought switching coils could possibly solve a low compression issue.

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He swapped coils because of the misfire codes for cylinders 2 & 4 thinking the coils may be the reason for the misfire.

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If it was a coil pack rather than coil on plug I might have tried swapping in a new coil pack (if it didn’t cost me anything - think a guy who’s had a parts car). But in this case with COPs and compression #'s like that? Swapping coils is … well, a long shot. All it did was show that that the 2/4 cylinders are likely slightly worse, compression-wise, than the 1-3s

A 2013 Corolla with 218,000 miles should still have life left in it. And if the body and interior are still decent, I’d replace the motor. Even $3500 is a good bet, and as long as the used motor has at least a one year warranty, it’s a good investment. If you replace the vehicle, you aren’t getting something newer, and in better condition for $3500. You might find something older with lower miles, but that’s a worse bet than a vehicle which you already own.

According to credit bureau statistics, the average monthly payment for a used car is over $500, and that assumes an average down payment. The average monthly payment for a new car is over $700, again assuming an average down payment. Therefore, this $3500 engine replacement pays for itself after only 7 months. Each month beyond month 7, which the car continues to run, it’s literally putting money back into your pocket, month after month.

Case in point, I have a 2002 Daewoo Lanos. I only paid $1800 for this car. I have done all kinds of repairs to this car, even major engine repairs. A few months ago, I paid a professional mechanic about $1200 to replace all the shocks and struts. The car might only fetch $1200 on the open market, but that’s not the point. Keeping it in good running condition is a good investment, because every month I’m not making a $500+ loan payment.

Once you have your Corolla repaired, you should drive it for as many years as possible and save your money. Use the funds to pay down student debt and invest toward your eventual retirement. Don’t fall into the “expensive new(er) car” trap.

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Since the engine is “shot” anyway, change the oil to a 5w30 to see if it helps any, oil weight is what helps the rings to seal for compression… if it makes it worse then change it back to the 0w20, what have you got to loose??..

But I am curious as well to who did the compression test also, the compression test has to be done with the throttle wide open (your vehicle is a drive by wire), and you should do a dry test and then add some oil into the cylinders to do a wet test, if the compression comes up with the wet test, then it is the piston rings, if it doesn’t change it, then it is something else, possibly even timing related as MikeInNH mentioned…

Those Corolla engines can go 500,000 miles with out doing internal repairs… I think we are missing something here… 200K mile Corolla is still breaking in the engine… lol

Was that before or after he knew of the low compression?

It doesn’t matter, the OP’s logic is sound. If all cylinders have essentially the same compression (60-70 psi) but only cylinders 2 and 4 are setting a misfire code, then it’s entirely logical to think the misfires are caused by something other than compression since cylinders 1 and 3 have the same compression but aren’t misfiring. And besides, this is a med student, not a mechanic, and it takes less than 5 minutes to check so why give the guy a hard time?