I recently bought a 1990 Civic Si that has had a rather loud clanking sound coming from the lower driver’s side part of the car. I knew the engine had problems when I bought it but everything else on the car is really good and it was only $600 so I couldn’t refuse the offer.

At first I thought It might be the water pump or the timing belt might just need to be tightened. I checked the water pump for any play to make sure it was spinning freely and wasn’t able to wobble and it seems fine. Next I checked the timing belt and it seemed to be pretty lose on one side and was vibrating a lot. I adjusted the timing belt and removed any slack in it and it seemed to be a lot better and there wasn't any more vibration.

When ever the car is running I can still hear the noise, it is really hard to determine where it is coming from because it doesn’t seem to be coming from one certain area. I brought my dad over to check it out and he thought that it might be one of the crankshaft bearings but both of us don’t know for certain.

Is there any way to tell if one or more of the crankshaft bearings has gone bad without taking the engine out or apart?

 

Make sure you didn't tighten the timing belt too much. When cold, there should be quite a bit of play in the front side of the belt, a couple inches. When the motor heats up, it expands and the belt will get tighter. Check it when the motor is hot, and you'll see what I mean. Too tight can break the belt or hurt the main bearings or cam journals.

 

It's pretty snug on both sides right now but before I tightened it it was pretty loose on the front but was making a horrible racket and I thought it was going to blow up. I'll have to readjust it tomorrow.

Could something else be loose down in that area that could be making all that noise and if the bearing was bad what would it sound like?

 

If it has a bad bearing,
The evidence should be in the oil pan..

Warm it up and drain the oil..Look for shiny metallic particles.
You could also cut the oil filter open and inspect the filter element
for any debris..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 88DXCRX &raquo;</TD></TR><TR><TD CLASS="quote">If it has a bad bearing,
The evidence should be in the oil pan..

Warm it up and drain the oil..Look for shiny metallic particles.
You could also cut the oil filter open and inspect the filter element
for any debris..
</TD></TR></TABLE>

That's a good ideal, I definately need to try that tomorrow and look to see if I see anything in the oil pan.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 88DXCRX &raquo;</TD></TR><TR><TD CLASS="quote">If it has a bad bearing,
The evidence should be in the oil pan..

Warm it up and drain the oil..Look for shiny metallic particles.
You could also cut the oil filter open and inspect the filter element
for any debris..</TD></TR></TABLE>

Just gonna post that

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by drdisco69 &raquo;</TD></TR><TR><TD CLASS="quote">Make sure you didn't tighten the timing belt too much. When cold, there should be quite a bit of play in the front side of the belt, a couple inches. When the motor heats up, it expands and the belt will get tighter. Check it when the motor is hot, and you'll see what I mean. Too tight can break the belt or hurt the main bearings or cam journals.</TD></TR></TABLE>

???? never heard that befor, i could understand if you were pushing on the tensioner or something, Then Maybe it would be to tight. But in all honesty i dont think the whole block will expand that much anyways, plus as the belt warms up its gonna get more flexable. So really im not what the expletive your talking bout , maybe a link or something on some info? As far as i know HONDA does not want "quite a bit of play on the front side of the belt." And if what you are saying is true then my car and a shitload of my customers cars should have broken belts, or spun bearings.

 

Some people do pull on the tensioner to put more tension on the belt when tightening it, and it's possible to put too much on it.

 

I wasn't able to pull off the oil pan today but I did start it up for a while and listened really good to find where the noise was coming from.

I definitely think the noise is coming from the oil pan area, it sounds pretty bad. The noise isn't that loud but I can definitely hear it inside the car.

If the bearing was bad what would it sound like and I did notice some smoke coming out the back but not sure if that's related.

 

a common thing with miatas is overtigtening the belt and cracking the crank...but you should never have a couple inches of play in a timing belt. You slip the belt and your cylinders will smack your valves THEN youll have problems.