What is compression psi of EFI Mehran?

Suzuki

Mehran

frozennova (Shehz) 2022-12-30 02:59:24 +0500 #1

I got a compression test done and two cylinders showed 120psi with one at 90psi.
90psi spark plug had oil on it

Not noticing any oil burning.
Mileage 85,000KM

What is EFI Mehrans compression?
Would I need an overhaul or just change valve seals?
Estimated cost?

Hassan1991 (Electrical Engineer ) 2022-12-30 03:07:53 +0500 #2

Less then 130psi is not good.
And difference shouldn't be more then 15-20 psi.
Your engine seems to be weak.

pwuser147983858371 (Raja Ahmed) 2022-12-30 09:43:23 +0500 #3

A healthy engine has 180-200psi standard compression. Your engine needs tear down.

helper_learner (helper_learner) 2022-12-30 12:41:45 +0500 #4

What abut the wet test?, or have you only done dry test?

frozennova (Shehz) 2022-12-30 14:39:24 +0500 #5

It was only dry test.
Would the cylinder with the oilly spark plug be classed as a wet test due to oil already being there?

Suzuki said dry PSI should be 120 on EFI, but I'm getting people saying it should be around 180.

Which should it be?

Hassan1991 (Electrical Engineer ) 2022-12-30 14:53:45 +0500 #6

Multiply compression ratio with atmospheric pressure. It should be close to it.

frozennova (Shehz) 2022-12-30 18:16:34 +0500 #7

Would compression ratio be found out from a compression test?
What is the ratio supposed to be?

Just for changing valve seals and head gasket would facing the head be recommended?

Hassan1991 (Electrical Engineer ) 2022-12-30 18:38:07 +0500 #8

No. It is the ratio of volume of combustion chamber and cylinder.
Search for engine specs to find that.
You have to dismantle the engine to check which parts need replacement.

dani_kk (Dmotorsports) 2022-12-30 20:01:41 +0500 #9

I've already got the query from the owner of mehran.
And I've told him, that it is oil ring. As he just shared the result with me of the compression test done by Suzuki & however we can conduct this test again and let him know the possible fix.

helper_learner (helper_learner) 2022-12-30 21:11:03 +0500 #10

@dani_kk and @frozennova, Do update the outcome

frozennova (Shehz) 2022-12-30 21:53:41 +0500 #11

Yes. I'll hopefully visit you tomorrow.

dani_kk (Dmotorsports) 2022-12-30 23:38:42 +0500 #12

Ok.

helper_learner (helper_learner) 2022-12-30 23:53:56 +0500 #13

Good Luck

dani_kk (Dmotorsports) 2022-12-31 15:52:44 +0500 #14

dani_kk (Dmotorsports) 2022-12-31 15:55:03 +0500 #15

Third cylinder has coolant droplets on edges.

However plug had no contamination of oil.

Compression was low.
Dry
140-140-130

Wet
200-190-200

Which means the top ring and second ring are bad.
However have proposed him the partial rebuild & full overhaul if required.

frozennova (Shehz) 2023-01-02 14:32:59 +0500 #16

Is a leak down test possible before rebuild?

Hassan1991 (Electrical Engineer ) 2023-01-02 15:52:35 +0500 #17

Isn't that oil?

helper_learner (helper_learner) 2023-01-02 22:51:33 +0500 #18

I don't think it is necessary, Since compression test has shown the health of rings.

nfssaad (Saad Ahmed Khan) 2023-01-03 09:22:11 +0500 #19

leakdown test is done before dismantling engine

dani_kk (Dmotorsports) 2023-01-04 01:14:14 +0500 #20

No it is green coolant droplets. No signs of oil on plug tips.