What is the proper operating compression PSI for a 1999 Chevy Suburban c1500 5.7L?

100

Asked by Jan 03, 2014 at 01:20 PM about the 1999 Chevrolet Suburban C1500 RWD

Question type: Maintenance & Repair

P0300 misfire - cylinders 2, 4, & 6 - already replaced all plugs/wires, cap/rotor, cleaned
throttle body, replaced crankshaft sensor, & throttle pedal sensor. Want do pressure test
to check for vacuum leaks but don't know the specs & have tirelessly searched the net.

17 Answers

80,385

Generally speaking, 150 psi or higher is good at cranking speed. Have you checked the fuel injectors? They might not be spraying or not spraying correctly. HTH. -Jim

8 people found this helpful.
100

Thanks, I finally found some info as well. I found it to be 9.4:1 KPA which seems to be in about the same range of what your giving. We will check injector's as well.

4 people found this helpful.
80,385

You're welcome. Glad to help. -Jim

2 people found this helpful.
100

There is definitely a differential in the cylinder/spark plug pressure #4 only had 32 PSI. I didn't bother checking all of them since there was more than a 10% difference in the 3 I checked. From what I understand its indicative of needing to replace the head gasket. So that may be my next venture.

3 people found this helpful.
80,385

I'd say so too. Especially if either of the cylinders "next door" ( 2 or 6) test equally low. That means the head gasket is blown between the two cylinders. Also, since the misfire codes are all on the same side(even numbered cylinders) that makes me think head gasket as well. But just to be 100% sure, test all 8. HTH. -Jim

3 people found this helpful.
100

Would there be a different diagnosis or outcome based on the other readings? I didn't think it would make a difference but I am no car specialist...lol I'm just a girl going off Chilton's and some information off the net.

3 people found this helpful.
80,385

Yes, If all 8 cylinders test low it's a jumped timing chain. But with those kinds of readings on all 8 cylinders the truck wouldn't run. If you get a low reading on a single cylinder or even on two cylinders that aren't adjacent to each other it's most likely a valve problem. If a valve is burned or stuck open you'll have a low or zero reading on that cylinder only. But two low readings side by side point to a blown head gasket. -Jim

5 people found this helpful.
10

I had a random misfire on both my chevy trucks with 5.7 engines, both with 200K + miles. Changed plugs, wires, cap, rotor, tps, map sensor, knock sensor, cleaned the maf sensor on my 98 chevy. Nothing helped, The truck even got worse. Replaced the distributor on the 98 and all was solved. So I replaced the distributor on the 97 without changing all the other stuff and it now runs perfectly. Got the distributors off ebay from kjmperformance for $55. The best thing about this part is it has an aluminum base, not plastic like the factory one so I'm hoping it's going to last at least as long at the original.

1 people found this helpful.

1999 chevy tahoe will only run if number 7 spark plug is off.Don't no y

30

I'm having problems as well number 1 cylinder reads 91 pounds of compression and the other 7 range between 45 to 65 and that's while running. Dk if it makes a difference or not whether it's started or not? ??? Any help you can give is greatly appreciated

1 people found this helpful.
80,385

JR08, those can't be good cylinder compression readings. With compression readings that low the engine wouldn't run. Compression tests are done with the engine cranking, throttle wide open, and the ignition system disconnected so the engine won't start. Are those readings in pounds per square inch (PSI)? If so, retest using a different compression test gauge set. Sounds like yours is faulty. The kind where the hose screws into the spark plug hole is best. HTH. -Jim

30

The gauge test we used is in psi and it screws into the plug hole n the test was done with engine running

1 people found this helpful.
80,385

Something isn't right. With compression readings that low the engine wouldn't run. Sounds like the gauge is faulty. HTH. -Jim

30

I'm going to get a new tester soon and will update

1 people found this helpful.
80,385

Ok, good. Yes, please keep us posted. -Jim

10

Also - this engine is famous for the intake manifold gasket leaking and this often causes misfire indications on cylinders. Check to make sure you have not been losing coolant and pressure check your coolant system. If you replace it, make sure you use the FelPro PREMIUM intake manifold gasket - not the standard one.

1 people found this helpful.

I went through a spell where I was getting misfire codes and replaced everything I could replace and finally just got a code reader and reset the code when it came up... Then one day I accidently fixed it. I replace the front and back Universal on the drive shaft. The misfire codes it seems are based on vibration sensors. The universals under load were putting those exact vibrations into the vibration detectors. haven't had the fault in years.

Your Answer:

Suburban

Looking for a Used Suburban in your area?

CarGurus has 22,043 nationwide Suburban listings starting at $1,800.

ZIP:

Chevrolet Suburban Experts

  • #1
    Andrew Olsen
    Reputation
    1,280
  • #2
    Neal Turner
    Reputation
    1,090
  • #3
    Eric Fritz
    Reputation
    1,020
View All

Related Models For Sale

Used GMC Yukon XL
230 Great Deals out of 13,005 listings starting at $1,952
Used Chevrolet Tahoe
675 Great Deals out of 38,596 listings starting at $995
Used GMC Yukon
333 Great Deals out of 22,560 listings starting at $2,900
Used Ford Expedition
420 Great Deals out of 22,320 listings starting at $1,500
Used Cadillac Escalade
241 Great Deals out of 12,201 listings starting at $2,999
Used Chevrolet Silverado 1500
1,869 Great Deals out of 159,082 listings starting at $1,200
Used Chevrolet Silverado 2500HD
364 Great Deals out of 29,588 listings starting at $2,718
Used Ford F-150
2,398 Great Deals out of 200,117 listings starting at $1,300
Used Lincoln Navigator
93 Great Deals out of 4,473 listings starting at $695
Used GMC Sierra 1500
816 Great Deals out of 60,745 listings starting at $1,495
Used Ford Explorer
943 Great Deals out of 71,545 listings starting at $695

Used Cars For Sale

2018 Chevrolet Suburban For Sale
33 Great Deals out of 10,456 listings starting at $39,299
2017 Chevrolet Suburban For Sale
52 Great Deals out of 3,316 listings starting at $29,922
2016 Chevrolet Suburban For Sale
22 Great Deals out of 804 listings starting at $28,795
2015 Chevrolet Suburban For Sale
36 Great Deals out of 1,425 listings starting at $19,300
2014 Chevrolet Suburban For Sale
20 Great Deals out of 373 listings starting at $14,500

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.