Intake Manifold Gasket Replacement
Zseven14x4
10-06-2008, 10:36 AM
I am looking to replace my intake manifold gaskets and was wondering if there is anything I should be made aware of before starting this project? I have a 99 Z71 Silvy Ext.cab 4x4 5.3 with a 171k. I am new to the site and have been reading and repairing several things as I go and must say....very helpful. Thanks to all.
2000CAYukon
10-06-2008, 10:43 AM
j cAT
10-06-2008, 10:55 AM
http://www.automotiveforums.com/vbulletin/showthread.php?p=2613117#post2613117
//2000CAYukon
this post is for the 5.7L engine ...the 5.3 L engine is different....
//2000CAYukon
this post is for the 5.7L engine ...the 5.3 L engine is different....
2000CAYukon
10-06-2008, 01:56 PM
this post is for the 5.7L engine ...the 5.3 L engine is different....
Sorry about that. I saw 99 and assumed 5.7. Do we have a thread on replacing the 5.3 intake gaskets?
//2000CAYukon
Sorry about that. I saw 99 and assumed 5.7. Do we have a thread on replacing the 5.3 intake gaskets?
//2000CAYukon
silicon212
10-06-2008, 02:28 PM
I am looking to replace my intake manifold gaskets and was wondering if there is anything I should be made aware of before starting this project? I have a 99 Z71 Silvy Ext.cab 4x4 5.3 with a 171k. I am new to the site and have been reading and repairing several things as I go and must say....very helpful. Thanks to all.
Any reason toward replacing these?
Note: This is all from memory so I might miss something, but this is the general flow. On this engine, the intake gaskets are easy to replace. There are no water passages through them, such as what you will find on earlier engines.
The intake manifold is held onto the engine with 10 10mm head bolts, 5 on each side. These bolts are 45 degrees in the head (vertical in the real world). The gaskets themselves are hard plastic, with a bead of silicone. They're fairly durable.
Once you get the intake off, you will see an aluminum plate which is bolted to the top of the block. In this plate, you will see two holes that are covered with a plastic cover with a wire coming out. Just for future reference, these are the knock sensors on this engine. That way, if you ever need to trace a knock sensor problem, this is where they are. The holes can get water in them over time, and this causes knock sensor maladies.
Any reason toward replacing these?
Note: This is all from memory so I might miss something, but this is the general flow. On this engine, the intake gaskets are easy to replace. There are no water passages through them, such as what you will find on earlier engines.
The intake manifold is held onto the engine with 10 10mm head bolts, 5 on each side. These bolts are 45 degrees in the head (vertical in the real world). The gaskets themselves are hard plastic, with a bead of silicone. They're fairly durable.
Once you get the intake off, you will see an aluminum plate which is bolted to the top of the block. In this plate, you will see two holes that are covered with a plastic cover with a wire coming out. Just for future reference, these are the knock sensors on this engine. That way, if you ever need to trace a knock sensor problem, this is where they are. The holes can get water in them over time, and this causes knock sensor maladies.
Zseven14x4
10-06-2008, 03:37 PM
To anwser to the question of why? I have a s.e.s. light and have 6 codes showing which are P0440, P0171, P0174, P0446, P0449, and P0507.
I do not know what all the codes represent, some help would be appreciated. I had a very trusted mechanic look at my truck and told me that GM had trouble with the intake gaskets and he also mentioned about a possible vaccum leak?? This is when I was told about this site and have been reading now for about 2 weeks. I was also told about the purge valve possibly sticking?? If so, where is this located? Appreciate all the help.
I do not know what all the codes represent, some help would be appreciated. I had a very trusted mechanic look at my truck and told me that GM had trouble with the intake gaskets and he also mentioned about a possible vaccum leak?? This is when I was told about this site and have been reading now for about 2 weeks. I was also told about the purge valve possibly sticking?? If so, where is this located? Appreciate all the help.
j cAT
10-07-2008, 10:46 AM
To anwser to the question of why? I have a s.e.s. light and have 6 codes showing which are P0440, P0171, P0174, P0446, P0449, and P0507.
I do not know what all the codes represent, some help would be appreciated. I had a very trusted mechanic look at my truck and told me that GM had trouble with the intake gaskets and he also mentioned about a possible vaccum leak?? This is when I was told about this site and have been reading now for about 2 weeks. I was also told about the purge valve possibly sticking?? If so, where is this located? Appreciate all the help.
this more like what is needed to help you out....
your 440 is the vent lines for the fuel tank...remove the intake manifold plastic cover and these small plastic lines must be connected....also look at the fuel tank and between the two...
446 the fuel tank basicly has pressure this is a no no as vapors will get into the atmosphere..
449 this means that the computer is not getting the correct feedback from the evaporative emissions solenoid...usually the solenoid defective...
507 means that your idle is 200++++ too high this is usually caused by a vacuum leak....
171/174 together usually mean that after the maf you have air entering the engine [un metered air]....
I would check all lines under the intake cover replace the PCV and replace the evaporative emissions solenoid ...
clear all codes and see what happens...
On your mechanic/repair shop I would consider finding a repair shop that ensures positively what is wrong before they steal your cash.... when the pro's guess you know is bend over time...
I do not know what all the codes represent, some help would be appreciated. I had a very trusted mechanic look at my truck and told me that GM had trouble with the intake gaskets and he also mentioned about a possible vaccum leak?? This is when I was told about this site and have been reading now for about 2 weeks. I was also told about the purge valve possibly sticking?? If so, where is this located? Appreciate all the help.
this more like what is needed to help you out....
your 440 is the vent lines for the fuel tank...remove the intake manifold plastic cover and these small plastic lines must be connected....also look at the fuel tank and between the two...
446 the fuel tank basicly has pressure this is a no no as vapors will get into the atmosphere..
449 this means that the computer is not getting the correct feedback from the evaporative emissions solenoid...usually the solenoid defective...
507 means that your idle is 200++++ too high this is usually caused by a vacuum leak....
171/174 together usually mean that after the maf you have air entering the engine [un metered air]....
I would check all lines under the intake cover replace the PCV and replace the evaporative emissions solenoid ...
clear all codes and see what happens...
On your mechanic/repair shop I would consider finding a repair shop that ensures positively what is wrong before they steal your cash.... when the pro's guess you know is bend over time...
Zseven14x4
10-07-2008, 07:54 PM
I will check the items listed as soon as this weekend coming up. The solenoid, can I pick this up at any auto store? And where my it be located on the truck? Replaced the PCV. I am Idling at 500 to 550 rpm?
So, hold off on the gaskets I take it.:smokin:
Thanks for the help, much appreciated.
So, hold off on the gaskets I take it.:smokin:
Thanks for the help, much appreciated.
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