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Strange Knocking Noise


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Hey guys, had the car parked for a little while, I finally got it back together and started it up for the first time in about a month and I started hearing a strange knock. I had taken apart the fuel injection system, the injectors and the injector seat just above the throttle body. The car will idle all day, I am afraid to drive it though due to the noise. The comes and goes, so its hard to pin point, however it sounds like either the water pump or idler pulley. I have noticed the oil pressure is very low. This scares me, could it be something with the oil pump? Thoughts?
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When my water pump gave out it sounded like there were rocks in the engine so that's a possibility. Does your oil pressure increase when you rev the engine?

You could always remove the water pump belt and start the car briefly to see

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The oil pressure does rise however barely gets a quarter of the way up the gauge. Not good.

 

my oil pressure was reading the same way when i first got my car and when i put the new engine in it was still reading low like that put an aftermarket oil guage that is the type with the plastic line on it and it was reading totally different so might be a bad or dirty sending unit for the guage as for the knock have you checked the tension on the timming chains cause that could be the cause for both of your problems

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I will get it up on the lift this weekend and swap out the oil pressure sender with a new one. I will see if that helps at all. The sound is definitely coming from the front of the engine. As of now I am thinking it is the water pump. I may simply pull the water pump belt and start the car real quick to see. Thanks for the help guys, I will give you an update after I get done this weekend and let you know what happens.
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It sounds to me like you may possibly have timing chain/balance chain slap against the chain guides/timing chain cover cuz the chains are stretched beyond limits and/or the chain guides are worn out..

 

Does your lady still have the balance shafts installed? If so, one or both of the rear shaft bearings may have headed south - especially with the low indicated oil pressure.

 

Usually when the oil pressure sender goes FUBAR oil pressure as read at the dash indicates pegged high. However if the electrical connector at the pressure sender is crudded up or oily it can cause the pressure to read off cuz of resistence at that connector. Pull the connector off and clean the metal terminals inside of it and on the sensor. See what pressure readings you have then.

 

For What It's Worth.

 

KEN

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Okay guys, I finally got the water pump belt off. The noise was still there. I took the A/C belt off. Noise was still there. Do the distributors on these ever make strange noises? It sounds like its coming from the front end of the motor, not the back as if it was a timing chain. Every time I apply the throttle, I hear the noise, sometimes it keeps making the sound after letting of the throttle, sometimes it just goes away. I am really blown away at this point. I find it hard to believe it could by my timing chain, however you guys know better than I do, any simple way to check it?
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It sounds like its coming from the front end of the motor, not the back as if it was a timing chain. I find it hard to believe it could by my timing chain, however you guys know better than I do, any simple way to check it?

 

The timing and balance shaft chain assemblies are in the front of the G54B T engine (closest side to the radiator) not the rear. ;)

 

Remove the valve cover and shine a flash light down the large rectangular hole in the head at the front of the engine. Try to move the chains as they head down. The chains should be under tension not loosey goosey. See '88 FSM page 9-28 and this link http://starquest.i-x...topic.php?t=944 - alto many of this links pictures are missing it still has good verbage in it.

 

I believe what you have done and the results you got points to stretched chains, worn chain guides and a worn out timing chain tensioner. BTW - engine oil pressure causes the timing chain tensioner to push against the timing chain maintaining correct tension provided that the tensioner's wear limits are not exceeded. If, as you say in your OP, that you have "very low" engine oil pressure, guess what? The tensioner ain't maintaining proper tension combined with a worn out tensioner is gonna cause chain slap.

 

I'll almost bet that when you drop the crankcase oil pan it is full of a black crud that has worn off of the chain guides and the timing chain tensioner. That crud MAY have trashed the internals of your engine oil pump which MAY be the root cause of your low oil pressure.

 

What year is your Lady and how many miles are on her?

 

Has the engine block ever been overhauled?

 

Do you still have the balance shafts installed?

 

I would also suggest that you download and read the FSM especially chapter 9 for a start. ;)

 

For What It's Worth.

 

KEN

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I did not know the chain is in the front... Sorry that sounded bad haha. My old lady is a 1989 Conquest, The miles on the odometer only read 47k, however judging by the condition of the car, I know that is incorrect. I was told that the motor was "rebuilt" less then 10k miles ago. I do not know what the rebuild consisted of, and it was done by not the owner I bought it off of, but the one before him. I tried to get information on the rebuild but couldn't get anything out of him as he did not know. I will have to pull the valve cover I guess... :( I am just trying to help the poor girl back to life, and everytime I fix one thing, I find something else wrong :(
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I did not know the chain is in the front... Sorry that sounded bad haha. My old lady is a 1989 Conquest, The miles on the odometer only read 47k, however judging by the condition of the car, I know that is incorrect. I was told that the motor was "rebuilt" less then 10k miles ago. I do not know what the rebuild consisted of, and it was done by not the owner I bought it off of, but the one before him. I tried to get information on the rebuild but couldn't get anything out of him as he did not know. I will have to pull the valve cover I guess... :( I am just trying to help the poor girl back to life, and everytime I fix one thing, I find something else wrong :(

if you pull the dipstick and look at the oil, is there any metal in it? or sparkles?

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An engine "rebuild" means different things to different people. Sounds like your engine got a cheapie rebuild or the "rebuilder" didn't know what they were doing.

 

It appears to me that you gotta pull the timing chain cover and the oil pan to see what ya got. Also pull the oil pump and check it's internals for evidence of wear and take a set of clearance readings as denoted in the FSM section 9.

 

If the oil pump internals are not within spec then it's time to pull a rod & a main bearing cap and see what they look like and take the bearing clearances using plasti-gage. Or better yet, pull them anyway so you have peace of mind when you are 100 miles away from home. If they are bad then we'll talk about the Aluminum cam bearings integral to the head.

 

For What It's Worth.

 

KEN

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Unfortunately, the old lady is at home right now and I am at school. I come home every weekend too see it, but only get a couple hours with it unfortunately. This weekend I will check my oil, and possibly pull the valve cover and timing chain cover to check for the condition of the chain. What do I look for? A large amount of slack in the chain?
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The timing and balance shaft chain assemblies are in the front of the G54B T engine (closest side to the radiator) not the rear. ;)

 

Remove the valve cover and shine a flash light down the large rectangular hole in the head at the front of the engine. Try to move the chains as they head down. The chains should be under tension not loosey goosey. See '88 FSM page 9-28 and this link http://starquest.i-x...topic.php?t=944 - alto many of this links pictures are missing it still has good verbage in it.

 

I believe what you have done and the results you got points to stretched chains, worn chain guides and a worn out timing chain tensioner. BTW - engine oil pressure causes the timing chain tensioner to push against the timing chain maintaining correct tension provided that the tensioner's wear limits are not exceeded. If, as you say in your OP, that you have "very low" engine oil pressure, guess what? The tensioner ain't maintaining proper tension combined with a worn out tensioner is gonna cause chain slap.

 

I'll almost bet that when you drop the crankcase oil pan it is full of a black crud that has worn off of the chain guides and the timing chain tensioner. That crud MAY have trashed the internals of your engine oil pump which MAY be the root cause of your low oil pressure.

 

What year is your Lady and how many miles are on her?

 

Has the engine block ever been overhauled?

 

Do you still have the balance shafts installed?

 

I would also suggest that you download and read the FSM especially chapter 9 for a start. ;)

 

For What It's Worth.

 

KEN

 

Unfortunately, the old lady is at home right now and I am at school. I come home every weekend too see it, but only get a couple hours with it unfortunately. This weekend I will check my oil, and possibly pull the valve cover and timing chain cover to check for the condition of the chain. What do I look for? A large amount of slack in the chain?

 

What to look for? Read my reply above and you REALLY NEED to read FSM section 9!!!.

 

For What It's Worth.

 

KEN

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