Engine knock and pinging on 3.7L Inline 5 - Hummer H3

My knocking sounds like pinging and only occurs when the engine is hot, usually accelerating locally and freeways, especially up hill. It does occur sometimes when the A/C is off but more frequently with the A/C on. I dont think I am overheating because I keep a close eye on the water temps on my scan gauge and it never exceeds 215 degrees, usually around 190-205 during daily driving. I'm almost positive its engine knock. Ive checked the stock plugs and they are fine, air filters clean, I tried several different 87-89 octane brands (recomended 87 from the factory), ran Chevron fuel system cleaner, etc. Dealer says everything is fine and gave it back to me with an update on the "software". I drove it home and it was still knocking and I had to take it back. Ive run Royal Purple and Mobil-1 synthetics every 5k miles since the rig hit 5k miles. This is really driving me nuts :( , Any ideas?

Category:

Autos & Vehicles

Tags:

• Engine
• knock
• pinging
• detonation

[emoneybagz23]

Ah! The Vortec 3.7 inline 5! One of the most horrible engines I have used in a truck. GM needs to kill this engine ASAP. The fuel economy is horrible and the power output is lame. GM should have placed a 4.3 liter V6 in the H3, Colorado, and Canyon.

[svinche1]

@7477238 BEST Inline 5 engines are from AUDI 2.2 Engine from Audi RS2 / S2 are capable for 1300Whp.Curently one guy called JONUS from Norway developing 1700Whp version from 2.2L inline 5. And Audi are First manufacturer that introduce Inline 5 in 1977. Volvo start to use Inline 5 ,after they acquire license from VW inline 5 Diesel (2.4L) and later produced their own inline 5 engines. p.s. GM 3.7 is real Shame for inline 5 engines :( ... watch?v=fZ7tHczJaIk watch?v=CYxeDCer0lc

[Viperfet]

@svinche1 Capable but not in stock form.

[saleenxxx]

@7477238 my volvo was I-5 turbo some sick shit man

[fastfiddler1625]

1993 Audi S-4 has I-5 turbo. Drives nice.

[truebassB]

@emoneybagz23 The 4.3Liter V6 was a hunkah junk,they replaced it with the better Vortec 4200 Inline 6,that engine would be a treasure if they have used it on vehicles other than GMT360,which btw is a bigger version of the Vortec 3700,better say the Vortec 3500 and 3700 is a smaller Vortec 4200,as the 4.3 V6 was a smaller version of the 5.7 V8.

Of course now the idiots dumped Vortec 4200 for the weak 'n boosted Ecoshit 3Liter V6s and Inline 4s.

[truebassB]

@svinche1 Tell him good luck from me,he will need it as much as 50 PSI to get there plus +200hp gain from other mods and total cost over 100 grands... If i was him i'd dump that little Inline 5 down the pit and put an Ls2 on it to get greater results with way less cost and boost (around 25 which is a realistic boost amount compared to 50),or if he doesn't want American at least an Audi V12.

[LittleBigMarcus]

try 92 octane, someone correct me if im wrong

[jasaircraft]

have you confirmed this is actual engine knock aka detonation by eliminating it with higher rating octane fuel?

[mustang2005]

@7477238 oo

[7477238]

@mustang2005 You didnt know I-5 cylinder engines didn't exist? They're not widely used but they are around. Volvos mostly use them today and the only car I ever drove with one was an Acura Vigor.