Firstly, I would like to introduce myself as this is my first post on the forum. I had no idea this forum existed and I'm glad I ran into it. My name is Pete and I have owned this98 Blazer LT 4.3 since brand new and it currently has 75K miles.

The car has been pretty solid for almost 10 years. Here's the quick run down of events that lead to this...

About 2-3 weeks ago I started up the car in the morning and was letting it run. For whatever reason I decided to go outside of the car and gave it a quick walk around to make sure everything looked good. I checked under the car and noticed coolant dripping. Upon closure examination I noticed the coolant was leaking from the intake manifold. I dropped off the car at the shop nearby and a few hundred dollars later, they replaced the intake manifold gasket and I was on my way.

That same day I noticed the heat wasn't working very well. Additionally I started to notice a horrible ticking noise almost like a popcorn machine. The ticking noise increases as the RPMs increase. I brought it back to the shop and said the heat isn't working and there is a horrible ticking noise.

I left the car there and came back later on the day to pick it up. The heat was now working and he said he blew out the lines and something must have been blocking the heater core. He said the ticking noise was most likely the oil pump going and was not able to supply enough oil to the upper valve train.

1) As a result of the mechanic changing the intake manifold gasket, could he have caused a problem elsewhere in the engine? What type of mistake could he have made that generated the ticking noise right after he changed the intake manifold gasket? It seems to coincidental that immediately after he worked on my car I developed that ticking noise.

That's the first question...

I drove the car around with the ticking noise for another week or so. The car performed as usual, no degradation in performance and no odd emissions coming from the exhaust.

I went around to a few other shops to see what they thought the problem was and they all said the oil pump is failing and causing this noise. The last shop I went to said that some of the lifters could be bad. I decided to let them change out all the lifters as this was the easiest and cheapest "fix" at the time. After they changed out all the lifters, the ticking noise was still present.

I've noticed that although the noise sounds like it's coming from the upper valvetrain, it is a bit louder towards the bottom of the engine.

2) Based on what I've observed, what do you think my problem may be?

Please excuse this long post but I am trying to provide as much information as possible. I would like to know if the mechanic who fixed the intake manifold gasket could have caused this new problem and what do you guys think the problem could be.

Thanks for your time and I greatly appreciate your responses.

Cheers!

 

Working on the lifters would be fixing the symptom and ignoring the cause. Another member had the same issue and lost his engine within a couple of days. If the oil pump is bad, replace it before damage is done. And no, replacing the manifold gasket did not cause the noise problem or the pump problem unless debris got into the engine oil gallery, which would not be likely if the mechanic knew what he was doing.

 

How can I diagnose that the oil pump is bad or heading south? The pressure according to the cluster guage is perfect. It's slightly above the half-way mark when the engine is cold and then levels offa bit below the half-way mark when the engine reaches operating temperature.

 

CHECK YOUR OIL PRESSURE. my oil pump just went out, and its not cheap to fix after what happens when an oil pump goes out, i have to replace the whole bottom end. make sure you dont have the same problem i did. you might spin a bearing. not good.

 

How can I check my oil pressure?

 

watch your oil pressure gauge, if itjumps, your pump may be going. check your oil level, make sure there is no metal shards in your oil, i had metal in my oil after my pump went.

 

I suggest connecting a manual oil pressure gauge to the engine and see what it says. Remember, an oil pump does not create pressure, it creates flow/volume. The engine design is what creates pressure by restriction to the flow. That's why two different typesof engines can use the same oil pump, yet have different operating oil pressures.
Although, if several shops have said the pump is bad, I would tend tolisten. They may have done a pressure test already, I don't know.

 

The noise is definitely coming from the bottom end and is not getting any better.

The hunt for a decent replacement motor begins...

What year engines make an eligible canididate for a direct swap?


Also, anyone in the NYC area that can recommend a reputable shop capable of this job?

 

Anything '96-'01 will be a direct swap. Sometime in '02 they changed some things around with the EGR system and the knock sensors, IIRC. But even then, you can swap over the intake & exhaust manifolds and re-do the wiring for the knock sensor and use the '02+ block/heads (and fuel injection spider).

 

Thanks for the info swartlkk