What is normal compression for is350?
03-14-18, 01:40 PM
#1
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What is normal compression for is350?
Just got a compression test for my IS350 and mechanic says all cylinders are at 150 psi. Is this normal psi range?
thanks!
thanks!
03-14-18, 02:05 PM
#2
Originally Posted by Lexus IS250/350 Repair Manual
HINT:
Always use a fully charged battery to obtain engine speed of 250 rpm or more.
NOTICE:
The measurement must be done as quickly as possible.
Standard compression pressure:
1.4 MPa (14 kgf*cm 2 , 199 psi) or more
Minimum pressure:
0.98 MPa (10.0 kgf*cm 2 , 142 psi)
Difference between each cylinder:
0.1 MPa (1.0 kgf*cm 2 , 15 psi) or less
NOTICE:
The measurement must be done as quickly as possible.
Standard compression pressure:
1.4 MPa (14 kgf*cm 2 , 199 psi) or more
Minimum pressure:
0.98 MPa (10.0 kgf*cm 2 , 142 psi)
Difference between each cylinder:
0.1 MPa (1.0 kgf*cm 2 , 15 psi) or less
Jeff
03-14-18, 02:33 PM
#3
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Hmm, interesting. So even though the manual states that readings should be 200 psi or higher a reading of 150 per cylinder is considered a normal, healthy engine as long as the numbers are within 15 psi of eachother?
03-16-18, 09:37 AM
#5
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03-17-18, 08:47 PM
#7
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No symptoms of low compression so far. I just bought the car at 100k miles Carfax 1 owner all dealer maintenance HOWEVER, upon checking the detailed dealer service notes I found one particular repair that got me very worried which is why I had the compression tested. I will post it below.
Service: MISC REPAIR
Description: MISC REPAIR ~ ~PLEASE INSPECT FOR NO START ~ ~MISC REPAIR ~ ~83633 VEHICLE WILL NOT START AFTER ELF CAMPAIGN. FOUND BENT VALVES IN # 1 CYLINDER DUE TO FOREIGN MATERIAL. REPLACED 2 INTAKE & 2 EXHAUST VALVES. SUBLET CYLINDER HEAD FOR VALVE SEAT REPAIR. ALSO REPLACED #1 PISTON. CRACK FOUND IN PISTON. NO OTHER ENGINE C
Service: MISC REPAIR
Description: MISC REPAIR ~ ~PLEASE INSPECT FOR NO START ~ ~MISC REPAIR ~ ~83633 VEHICLE WILL NOT START AFTER ELF CAMPAIGN. FOUND BENT VALVES IN # 1 CYLINDER DUE TO FOREIGN MATERIAL. REPLACED 2 INTAKE & 2 EXHAUST VALVES. SUBLET CYLINDER HEAD FOR VALVE SEAT REPAIR. ALSO REPLACED #1 PISTON. CRACK FOUND IN PISTON. NO OTHER ENGINE C
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03-18-18, 10:01 AM
#8
^^^ Ouch!!!! Somebody F'd up!
Off hand a dealership should have replaced that head vs repair it. As for the actual compression values read, there are a lot of variables. Was this done at home? Do you have the gauge? You might verify the inlet port is not restricted and if possible connect it to shop air and see if 125psi is indeed 125psi on your gauge.
The most obvious check is are all the plugs burning the same and look the same. Do they?
Off hand a dealership should have replaced that head vs repair it. As for the actual compression values read, there are a lot of variables. Was this done at home? Do you have the gauge? You might verify the inlet port is not restricted and if possible connect it to shop air and see if 125psi is indeed 125psi on your gauge.
The most obvious check is are all the plugs burning the same and look the same. Do they?
03-18-18, 12:26 PM
#9
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My mechanic was the one who did the test and I am not sure how they did it or what gauge they used.
I am going to have the spark plugs changed this week as It is unclear whether the previous owner had hem replaced at 60k so I will have a look at the old ones when I swap them out.
It sure is convinient for everyone but me that this information doesn’t have to be disclosed. I don’t think I will ever trust Carfax again as I surely wouldn’t have bought the car had I known about this.
I am going to have the spark plugs changed this week as It is unclear whether the previous owner had hem replaced at 60k so I will have a look at the old ones when I swap them out.
It sure is convinient for everyone but me that this information doesn’t have to be disclosed. I don’t think I will ever trust Carfax again as I surely wouldn’t have bought the car had I known about this.
03-18-18, 06:27 PM
#10
Carfax is crap... Like Fake News... lol
Bumpers, fenders, doors, a world of sin including drivetrain repairs (not insurance related) flies completely under the radar on many cars as people don't want to report stuff for fear of rate increase. And ya, stuff that ain't covered by insurance.
Buyer be ware. Carfax doesn't cover everything.
So was the damaged cylinder low on pressure? If Not, don't worry and drive it. That said I would have passed too!
Private sale or ????
Bumpers, fenders, doors, a world of sin including drivetrain repairs (not insurance related) flies completely under the radar on many cars as people don't want to report stuff for fear of rate increase. And ya, stuff that ain't covered by insurance.
Buyer be ware. Carfax doesn't cover everything.
So was the damaged cylinder low on pressure? If Not, don't worry and drive it. That said I would have passed too!
Private sale or ????
03-18-18, 10:03 PM
#11
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Bought it at an Audi dealership. All the cylinders were 150psi according to my mechanic. The one thing I have noticed about the car is that it makes a ticking noise (not the direct injectors) when the engine is cold that goes away once the engine warms up. Is that common with these cars?
03-19-18, 06:58 AM
#12
The high pressure fuel pump for the DI on the rightside valve cover makes a pretty solid thump (seems like more of thump than a tick), but yes. Its louder than the injectors and is a normal sound. Mine is louder when cold too.
If you really want to isolate the sound, place a very long handled screw driver handle to your ear and move the tip about touching various areas. Don't hesitate to listen in on the water pump either. Many have had them fail under 100k mi. It should sound smooth and consistent. Like a constant "whirrrrrrrrrr".
If you really want to isolate the sound, place a very long handled screw driver handle to your ear and move the tip about touching various areas. Don't hesitate to listen in on the water pump either. Many have had them fail under 100k mi. It should sound smooth and consistent. Like a constant "whirrrrrrrrrr".
03-19-18, 09:06 AM
#13
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When the engine is at normal operating temp I can always hear the injectors and fuel pump ticking/thumping while the car is sitting at idle however when I start to accelerate I can’t hear the sound they make anymore. When I first start the car in the morning however the ticking noise I am referring to occurs with light acceleration (it’s not super loud but noticeable). Is this just the injectors/fuel pump making this noise?
03-19-18, 09:25 AM
#14
Honestly, I wouldn't worry to much about it.
You have even pressure to all 6 cylinders. If one hole was low/high, or if one whole bank of cylinders was low/high I'd worry.
There are so many variables when it comes to this test. Was the throttle opened, was the engine warmed up, did the engine make 4 or 10 complete revolutions, was it on a battery charger, was it performed during the 2nd blood moon shortly after a goat was sacrificed....
You have even pressure to all 6 cylinders. If one hole was low/high, or if one whole bank of cylinders was low/high I'd worry.
There are so many variables when it comes to this test. Was the throttle opened, was the engine warmed up, did the engine make 4 or 10 complete revolutions, was it on a battery charger, was it performed during the 2nd blood moon shortly after a goat was sacrificed....
03-19-18, 03:35 PM
#15
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No goats were sacrificed so I probably need to redo it lmao. I am a bit concerned about the ticking tho If it’s not coming from the fuel pump or injectors. Sounds like it could be lifters maybe...
Last edited by AndaleFish; 03-19-18 at 03:41 PM.