LQ4 Help?!?!? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Bigo Serge · 03-02-2011, 12:37 AM

What up, fellas,
I need help on decoding my LQ4 engine I bought for my 72 cheyenne. It has the complete motor with the computer and harness. The computer has been flashed already and the harness has been trimed down by taking off all the smog and unneccesary stuff.
My help is needed in identifying if it is a LQ4 or LQ9. I know one has flat pistons and the other doesnt. Will the casing number tell me anything? I was told the engine came out of a 03 tahoe, but I have not heard of a tahow with this engine. I know they come in the express vans, escalades, denali, and some HD trucks. Any info will help out a lot. Thanks for your input.

ls1nova71 · 03-02-2011, 01:52 AM

Never seen a Tahoe with a 6.0 either. Under the power steering pump bracket it will either say 6.0 or 4.8/5.3, if you've checked that and for sure know it's a 6.0, then the only to tell the difference between a lq4 and a lq9 is to either pull a head and check the pistons like you said, or you can pull a spark plug and look inside with a small flashlight.
Posted via Mobile Device

Bigo Serge · 03-02-2011, 08:08 PM

Thanks ls1nova71. I looked behind the block, on the passenger side and it's definitely a 6.0. I'm gonna have to try looking after removing a plug.

ls1nova71 · 03-03-2011, 12:32 AM

Another tell-tale sign of an LQ9 is they 'usually' have vacuum power brakes, where as the LQ4's will almost always have hydroboost. So you can check the back of the intake for either a plug or a nipple for the PB hose, and the power steering pump for the extra return line fitting.

03-02-2011, 12:37 AM	#1
Bigo Serge Registered User Join Date: Dec 2009 Location: Wichita, ks Posts: 59	LQ4 Help?!?!? What up, fellas, I need help on decoding my LQ4 engine I bought for my 72 cheyenne. It has the complete motor with the computer and harness. The computer has been flashed already and the harness has been trimed down by taking off all the smog and unneccesary stuff. My help is needed in identifying if it is a LQ4 or LQ9. I know one has flat pistons and the other doesnt. Will the casing number tell me anything? I was told the engine came out of a 03 tahoe, but I have not heard of a tahow with this engine. I know they come in the express vans, escalades, denali, and some HD trucks. Any info will help out a lot. Thanks for your input. __________________ Pick'em up, lay'em down, Oh Yeahhh

03-02-2011, 01:52 AM	#2
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,119	Re: LQ4 Help?!?!? Never seen a Tahoe with a 6.0 either. Under the power steering pump bracket it will either say 6.0 or 4.8/5.3, if you've checked that and for sure know it's a 6.0, then the only to tell the difference between a lq4 and a lq9 is to either pull a head and check the pistons like you said, or you can pull a spark plug and look inside with a small flashlight. Posted via Mobile Device Last edited by ls1nova71; 03-03-2011 at 12:34 AM. Reason: stupid auto correct!

03-02-2011, 08:08 PM	#3
Bigo Serge Registered User Join Date: Dec 2009 Location: Wichita, ks Posts: 59	Re: LQ4 Help?!?!? Thanks ls1nova71. I looked behind the block, on the passenger side and it's definitely a 6.0. I'm gonna have to try looking after removing a plug. __________________ Pick'em up, lay'em down, Oh Yeahhh

03-03-2011, 12:32 AM	#4
ls1nova71 Registered User Join Date: Dec 2009 Location: Independence Mo Posts: 4,119	Re: LQ4 Help?!?!? Another tell-tale sign of an LQ9 is they 'usually' have vacuum power brakes, where as the LQ4's will almost always have hydroboost. So you can check the back of the intake for either a plug or a nipple for the PB hose, and the power steering pump for the extra return line fitting.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.