x2

 

i would suggest using a 160 stat and using a front crossover tube and using it on the rear. then tie the front tube to rear tube before it goes to the rad. keeping the motor as cool as possible is easiest way untill someone can figure out exactly what hte issue is

also make sure you run Efans and try to use a 34" rad with an older core that is actually 3" thick instead of the stock 1.5"

 

I have the factory temp sender in the drivers front, and an electric temp gauge in the passenger rear. normal driving the rear gauge is 10+ degrees hotter, but when I run it through the gears, full throttle...the rear spikes over 200 and the front sender reads 170........as soon as I let off the gas the rear levels back out..

 

I found this as well on LS1 this morning...
https://ls1tech.com/forums/showthrea...5995&highlight

I was thinking of drilling and taping the steam holes, but I think they will crack...

 

Has anyone considered the exhaust side causing #7 to blow? If your exhaust is too big or too small then the lack of scavenging would occur... The lack of scavenging would not get out all the exhaust gases and most importantly the HEAT in that cylinder, thus increasing the detonation due to heat.... Isn't this why most guys run a richer mixture so they can use the unburnt fuel to cool the exhaust gases? From what I have read a tuned exhaust system will increase the Volume efficiency of a motor, actually sucking the air out of the combustion chamber via the headers/manifold... I am probably wrong but I think it is worth a look...

 

Interesting...this is what I was wanting to do, only I wanted to put a second temp sender in the brass plug next to the #7 cylinder in the block. I still want to do it, but haven't had time to mess with it.

 

Why is just #7 the problem with this concern. We use to see a bunch of these and #7 always had a ton of missfires and #8 would have some, but not even close to #7 cylinder? Just thinking out loud?




xTooltipElement
Service Information 2000 Chevrolet Chevy C Silverado - 2WD | Sierra, Silverado, Suburban, Tahoe, Yukon (VIN C/K) Service Manual | Document ID: 1863957
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#PIP3055A: P0300 Cylinder 7 Misfire Due To Fuel System Contamination - keywords CEL contaminated DTC engine gas L59 L76 L92 LC9 LMG LR4 LM7 LY2 LY5 LY6 LQ4 LQ9 miss P0302 P0307 P0308 SES tank water - (Sep 26, 2006)


Subject: P0300 Cylinder 7 Misfire due to Fuel System Contamination


Models: 2001-2007 Cadillac Escalade

1999-2007 Chevrolet Avalanche, Express, Silverado, Suburban, and Tahoe

1999-2007 GMC Savana, Sierra, Yukon

2003-2007 Hummer H2




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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
A dealer may encounter a customer concern of a SES light on and a engine misfire. The misfires will accumulate mostly on the number 7 cylinder. A possible cause could be fuel contamination. If present, the contaminated fuel will collect around the #7 fuel injector due to the fuel rail configuration in these vehicles. Fuel contamination can also cause random misfires to occur on other cylinders.

Recommendation/Instructions:
If the published misfire diagnostic does not isolate the concern, the following suggestions may help if the misfire is related to fuel contamination:

Complete the SI repair procedure for Fuel Rail Assembly Replacement. When the fuel feed pipes are removed, cap off the fuel rail inlet so the contents can be inspected for contamination. Drain the fuel rail into a clean approved container, and inspect the fuel.
If contamination is found, follow the current SI Fuel System Cleaning procedure.
Once the fuel system is cleaned, refill the fuel system with new gasoline.
Advise the customer that they should only use gasoline from a high quality, high volume filling station.
If this is a 99 - 00 Chevrolet Silverado or GMC Sierra, also review 00-06-04-024. This bulletin relates to an updated EVAP vent valve to prevent water from being drawn in through the EVAP Vent Valve, which may lead to repeat fuel contamination.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

 

Im not saying this is the problems why #7 piston goes bad. Just shedding some light on some problems we see at the dealership with fuel delivery.

 

I really think it's a combination of several factors. #7 seems to have the worst fuel delivery, some say it gets the highest airflow due to intake manifold design, and some say it's a cooling problem. I bet it's a combination of all 3.