Dear all,

my Blazer boke down. I relalized rough idle and then lifter noise.
Compression test showed low compression on clylinder 1.

I took the head off and removed the valve and saw some metal part sticking in my intake valve.

Have you see this failure mode before. Some part from the thottle body broke off and dropped in.

What a disaster!!!

BR
Bob

 

Wtf!!!

 

did you or someone try to remove the baffle and fail? that's what it looks like. No way that just happened on it's own

 

Iam diving my blazer the last 5 years. You are wrong. Nobody touched that baffle.

You can see that the metal cracked around the rivets and it got sucket in.

That is a nice failure mode. After this baffle broke of I realized a lean mixure on low rpm.
This thing controls the air flow @ part load.

Am I the only one who had this failure mode in the GM World.

BR
Bob

 

Here some photos of my worn out valve seats which is the root cause for my low compression.

Is this normal for 160 k mls.

 

i know that removing that baffle (broken peice) is a popular mod that in the end doesn't help a whole lot. You said you've been driving it for 5 years, I'm sure your blazer is older than that. Metal doesn't just crack

 

The baffle on my old 2000 Bravada was aluminum which is prone to fatigue over time. However, I would bet that at some point in time the baffle was tampered with resulting in a loose fit to the rivets which allowed the baffle to wiggle during engine operation. This movement is what resulted in the failure of the baffle.

You are going to want to pick up a new throttle blade with the factory baffle. Reason being, the baffle had a smaller idle bleed hole in it than the blade itself has or possibly install a rivet into the hole left in the throttle blade and drill out the center, restricting the hole. If left as is, you will have a high idle. When this mod is done correctly, the lower part of the baffle gets cut off leaving the portion riveted to the blade intact. As stated, this mod doesn't do a whole lot for performance and really only increases part throttle response.

 

Thank you swartlkk for the support.

since my heads are off and here in Germany nobody has the tool on hand for a valve job. They have machine shops for BMW & VW but nobody uses 46mm exhaust valves and 38mm intake valve with a valve stem diameter of 8.65mm.

May you be able to point out some Newway tool numbers for the guide and the valve seat grinder for intake & exhaust.

I like to use a hand grinder and I am not sure what shall I buy.
There are to many english sizez on the market.

BR
Bob

 

Have you tried just hand lapping the valves with some grinding compound after applying bluing on the valve face to see how well they'll seat as they are?

As far as Neway cutters go, I have no experience with them or any other cutters used for doing a valve job. That is something I entrust to the machine shop doing the work.

 

Yes I did. I cannot get then air leak tight.

I have a mighty vac and I am sucking vacum from the cylinder head side.
One side has some pitting and now this side leak air much more then all the others.

BR
Bob