Now my engine is knocking!!!!!!!!!!!!!!

[mountie1982]

I have a 1997 Blazer 2 door 4x4 4.3L V6 vortex. It has high mileage but runs 100% fine. I was driving the other day and heard a ticking sound comming from the engine. I pulled over thinking I was low on oil. I wasnt the oil in both the engine and tranny are full. The noise is comming from the engine. It sounds like the driverside near the top but I am not 100% sure of that but thats what I think. I have very little motor repair skills but I know people who are good with engines. I know its hard to say what it is without hearing it but if you think you may know where i should start that would a great help.


Thanks.

[mrfirebird]

wow. my kids 94 did something like that a couple weeks ago and it dropped a push rod from under the rocker arm. put it back in and all seems fine. hope yours is as an eazy fix. maybe the knock sensor,too

[ricksza]

Is the oil pressure gauge reading normal? Is the ticking noise engine speed related? At an idle, is the ticking real fast, or does it seem slow enough to count up (slow might indicate a lifter or rocker porblem)? First thing I would do is take the belt off to make sure that noise isn't coming from the alternator or AC compressor.

[BlazerLT]

Originally Posted by mountie1982

I have a 1997 Blazer 2 door 4x4 4.3L V6 vortex. It has high mileage but runs 100% fine. I was driving the other day and heard a ticking sound comming from the engine. I pulled over thinking I was low on oil. I wasnt the oil in both the engine and tranny are full. The noise is comming from the engine. It sounds like the driverside near the top but I am not 100% sure of that but thats what I think. I have very little motor repair skills but I know people who are good with engines. I know its hard to say what it is without hearing it but if you think you may know where i should start that would a great help.


Thanks.

Have you changed the cap and rotor lately?

[tom3]

I'd start with an oil and filter change. If that improves it you may have a hydraulic lifter going bad. If you don't hotrod it, should run for a long time with some luck.

[BlazerLT]

Originally Posted by tom3

I'd start with an oil and filter change. If that improves it you may have a hydraulic lifter going bad. If you don't hotrod it, should run for a long time with some luck.

I highly doubt it is just a lifter.

A loud knock is not the sign of a bad lifter. Lifters will tap.

[mountie1982]

The oil pressure gauge is reading normal. The ticking noise starts after it warms up. At an idle the ticking slow and with increased rpm the sound gets louder and faster. It is not the a/c unit I can hear its comming from the block. I think mrfirebird is right. Now that I have had a chance to look into it better and have a friend look at it I am thinking its just the lifter. Its no going to be a fun job.


Thanks for your input guys!!!

[BlazerLT]

Can you post a sound clip of this sound?

[amceagle]

i was talking to someone who has a blazer. it had high miles ran good untill it threw a cam bearing.

[hunter01]

Place a short piece (1-1/2") of vacuum hose on the posts on top of the distributer and then put the plug wires back on on top of the pieces of hose and start the engine. (vacuum hose conducts electricity) Then You take a test light and touch each piece of hose one at a time to ground out that cylinder and see if the knock goes away or the noise changes. This should tell you which cylinder is making the noise.

P.S You could just take the test light and stab it through the plug wire boots on the top of the distributor cap but this will let moisture in so you would have to seal the holes with silicone.

[BlazerLT]

Originally Posted by hunter01

Place a short piece (1-1/2") of vacuum hose on the posts on top of the distributer and then put the plug wires back on on top of the pieces of hose and start the engine. (vacuum hose conducts electricity) Then You take a test light and touch each piece of hose one at a time to ground out that cylinder and see if the knock goes away or the noise changes. This should tell you which cylinder is making the noise.

P.S You could just take the test light and stab it through the plug wire boots on the top of the distributor cap but this will let moisture in so you would have to seal the holes with silicone.

????

What the..........

[molehole]

Originally Posted by hunter01

Place a short piece (1-1/2") of vacuum hose on the posts on top of the distributer and then put the plug wires back on on top of the pieces of hose and start the engine. (vacuum hose conducts electricity) Then You take a test light and touch each piece of hose one at a time to ground out that cylinder and see if the knock goes away or the noise changes. This should tell you which cylinder is making the noise.

P.S You could just take the test light and stab it through the plug wire boots on the top of the distributor cap but this will let moisture in so you would have to seal the holes with silicone.

Ummm.... Ok thats a new one to me. Am I wrong but rubber does not conduct electricity??? Like your car is highly unlikely to get struck by lightening because of rubber.

[hunter01]

There's carbon in the rubber.

[BlazerLT]

Originally Posted by hunter01

There's carbon in the rubber.

Hunter, honestly, thinking that a rubber tube conducting electricity is a little beyond the realm of realism don't you think.

[hunter01]

I used this method to diagnose a bent wrist pin in a 350 small block. I thought it sounded crazy when I first heard about it but it works. Try it.