bunchz71
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This past week I have done some engine maintenance to my 5.7 Vortec. I will call this the DOMINO Effect. You will understand after you read this post.
My 1999 Tahoe now has 180,000 miles on it. I have a Rough Country Suspension Lift with 35" Tires. 4:45 Gears, Tom Woods Rear CV Double Cardon Driveshaft. My Tahoe had become sluggish a little, sometimes dying in gear and just not running right, and on top of that, hard to start in the mornings. After reading several forums, I come to the conclusion that it was possible my Fuel Psi reg was bad and was leaking gas, causing my motor to flood when it was cold, and therefore being hard to start. I tried the minor things first, like coolant temperature sensor, but still same issue (referring to cold starts). Since now, I have 180K miles, I did not want to tear the upper intake cover off and end up having to go back later replacing the spider injectors. So, if I was going to change the regulator, I decided to go ahead and change the spider injectors while I was there. This converted from SCPI to Multi-port. Here is where the Domino effect starts. Since I already had the AC off, I decided to change the water pump while I was this far. The water pump had a small leak around the back metal plate that dripped from time to time, so it obviously was time. It never leaked on the driveway, but it would always be wet around the gasket area. Now, I am thinking, I am right here, I might as well put a new timing chain on it while I am this far in, which also involves pulling the oil pan to get the front gasket to seal proper. Since the oil pump was original, I decided to change the oil pump while I had the oil pan off (no brainer IMO). Changing the oil pan gasket was a PITA, had to take off exhaust, and take one motor mount bolt off (drivers side), take off two nuts on rear transmission mount, and jack up the transmission to allow enough clearance to slide pan out. So now that I have all this apart, I look everything over really well and also decide to change out the oil coolant lines. they were caked with dirt and grime and showed signs of leaking a very small amount. I also changed out the fan clutch, since it came with the water pump kit. The distributor that was in it, I bought from a junk yard, and decided, while its out, why not replace it too. I wanted to eliminate the possibility of a bad cam sensor also (this was a wise choice, distributor hold down clamp made timing not adjustable, with engine TDC #1 after new timing chain was installed, and timing mark lined up, I set the distributor in pointing at #1 cylinder and the bolt hole lined up perfectly. If the rotor was not pointing at #1 and the bolt hole lined up for the hold down, you were off).
Here is the distributor I bought.
https://www.amazon.com/gp/product/B006CUWF8C/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
After many hours of tearing apart and putting back together, my Tahoe started immediately when I cranked it and purred like a kitten. No CODES, which always popped up when the timing was off. It was a lot of work and many hours to do, but I cannot express how happy I am with the results. What a difference.
Also, before I did all this, I ran a compression test on all cylinders. All cylinders had 160 - 170 psi compression. I think this engine will probably last me forever now and hopefully I luck out and dont have to ever swap it.
Just thought I would share for those who may have some a engine miss, and poor performance from high mileage.
bunchz71
My 1999 Tahoe now has 180,000 miles on it. I have a Rough Country Suspension Lift with 35" Tires. 4:45 Gears, Tom Woods Rear CV Double Cardon Driveshaft. My Tahoe had become sluggish a little, sometimes dying in gear and just not running right, and on top of that, hard to start in the mornings. After reading several forums, I come to the conclusion that it was possible my Fuel Psi reg was bad and was leaking gas, causing my motor to flood when it was cold, and therefore being hard to start. I tried the minor things first, like coolant temperature sensor, but still same issue (referring to cold starts). Since now, I have 180K miles, I did not want to tear the upper intake cover off and end up having to go back later replacing the spider injectors. So, if I was going to change the regulator, I decided to go ahead and change the spider injectors while I was there. This converted from SCPI to Multi-port. Here is where the Domino effect starts. Since I already had the AC off, I decided to change the water pump while I was this far. The water pump had a small leak around the back metal plate that dripped from time to time, so it obviously was time. It never leaked on the driveway, but it would always be wet around the gasket area. Now, I am thinking, I am right here, I might as well put a new timing chain on it while I am this far in, which also involves pulling the oil pan to get the front gasket to seal proper. Since the oil pump was original, I decided to change the oil pump while I had the oil pan off (no brainer IMO). Changing the oil pan gasket was a PITA, had to take off exhaust, and take one motor mount bolt off (drivers side), take off two nuts on rear transmission mount, and jack up the transmission to allow enough clearance to slide pan out. So now that I have all this apart, I look everything over really well and also decide to change out the oil coolant lines. they were caked with dirt and grime and showed signs of leaking a very small amount. I also changed out the fan clutch, since it came with the water pump kit. The distributor that was in it, I bought from a junk yard, and decided, while its out, why not replace it too. I wanted to eliminate the possibility of a bad cam sensor also (this was a wise choice, distributor hold down clamp made timing not adjustable, with engine TDC #1 after new timing chain was installed, and timing mark lined up, I set the distributor in pointing at #1 cylinder and the bolt hole lined up perfectly. If the rotor was not pointing at #1 and the bolt hole lined up for the hold down, you were off).
Here is the distributor I bought.
https://www.amazon.com/gp/product/B006CUWF8C/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
After many hours of tearing apart and putting back together, my Tahoe started immediately when I cranked it and purred like a kitten. No CODES, which always popped up when the timing was off. It was a lot of work and many hours to do, but I cannot express how happy I am with the results. What a difference.
Also, before I did all this, I ran a compression test on all cylinders. All cylinders had 160 - 170 psi compression. I think this engine will probably last me forever now and hopefully I luck out and dont have to ever swap it.
Just thought I would share for those who may have some a engine miss, and poor performance from high mileage.
bunchz71
