Bad compression or maybe something else?

30

Asked by Nov 26, 2017 at 01:09 AM about the 2001 Toyota Corolla

Question type: Maintenance & Repair

I bought a Toyota Corolla and after a 120 mile road
trip I got it home and did a compression test and it
was low in 2 of the 4 cylinders :(
I gave it 4 hours and did a compression test again,
but now all 4 cylinders run great compression.  I
took it for a good drive to warm it up and test the
compression again and it still reads good
compression.  It has a misfiring issue and says it
runs lean.  Could anyone explain why the
compression randomly got better? Maybe I just
tested it wrong the first time but I was pretty
confident I did it all right. any other advice is great.
Thanks!

8 Answers

500

Were the two bad cylinders adjacent?Possible beggining of head gasket leak.

2 people found this helpful.
30

That was my thought. I really just wanted the engine out of the car so when I bring out the engine would it be easy to replace the head gasket?

1 people found this helpful.
500

I would do the teat a few more times before I condemn the head gasket.it is not absolutely necessary to pull the engine to replace the head gasket. Was it two cylinders next to each other? Check for vacuum leaks and check injectors and injector Orings

2 people found this helpful.
500

Sorry for the typo.That should read "I would to the TEST..."

1 people found this helpful.
500

How many miles are on this car?

1 people found this helpful.
30

They were the two adjacent cylinders in the middle. I would also mention the spark plugs that were in the middle had white tips so the engine definitely got very hot at some point. I just don't understand how the compression somehow just became normal does anyone have input on that? And also thanks so much for all the quick input

2 people found this helpful.
91,055

White tips on the spark plugs is an overly lean air/fuel mixture. Either too much air or not enough fuel. The low compression on the two adjesent cylinders is a head gasket. Possibly when the engine is cold and everything contracts the head gasket is sealing. When the engine is warm/hot everything expands and the head gasket isn't sealing properly. What are the readings of the two low cylinders? Sounds like they're still firing, but lean. HTH. - Jim

Best Answer Mark helpful
500

I had a Lancer that had a similar head gasket problem. The cooling system was full of rust(bad design). It seems the circulating rust would seal the head gasket for awhile,then get dislodged. And on and on.Like a bad chemical sealent However, Js08016s Cold/warm theory is probably correct. Head bolts and theyre torque could also be a factor. You still havent mentioned how many miles are on this car?

1 people found this helpful.

Your Answer:

Corolla

Looking for a Used Corolla in your area?

CarGurus has 62,615 nationwide Corolla listings starting at $988.

ZIP:

Toyota Corolla Experts

  • #1
    tennisshoes
    Reputation
    2,160
  • #2
    Jeff Polhemus
    Reputation
    2,120
  • #3
    tenspeed
    Reputation
    1,990
View All

Related Models For Sale

Used Toyota Camry
1,486 Great Deals out of 74,726 listings starting at $1,299
Used Honda Civic
949 Great Deals out of 61,754 listings starting at $1,500
Used Honda Accord
1,176 Great Deals out of 82,578 listings starting at $800
Used Toyota RAV4
1,068 Great Deals out of 44,809 listings starting at $1,995
Used Hyundai Elantra
802 Great Deals out of 50,875 listings starting at $500
Used Nissan Altima
1,552 Great Deals out of 76,002 listings starting at $1,200
Used Nissan Sentra
899 Great Deals out of 56,500 listings starting at $899
Used Toyota Tacoma
793 Great Deals out of 48,707 listings starting at $2,000
Used Toyota Yaris
51 Great Deals out of 8,368 listings starting at $1,850
Used Toyota Prius
315 Great Deals out of 10,374 listings starting at $1,995
Used Honda CR-V
1,076 Great Deals out of 72,063 listings starting at $1,900
Used Toyota 4Runner
439 Great Deals out of 28,004 listings starting at $1,500
Used Ford Focus
1,029 Great Deals out of 38,249 listings starting at $1,695

Used Cars for Sale

2019 Toyota Corolla For Sale
8 Great Deals out of 33,505 listings starting at $13,995
2018 Toyota Corolla For Sale
106 Great Deals out of 4,062 listings starting at $11,300
2017 Toyota Corolla For Sale
188 Great Deals out of 6,039 listings starting at $8,830
2016 Toyota Corolla For Sale
396 Great Deals out of 7,880 listings starting at $7,250
2015 Toyota Corolla For Sale
159 Great Deals out of 2,866 listings starting at $7,335

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use. Content will be removed if CarGurus becomes aware that it violates our policies.