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Discussion Starter · #1 · (Edited)
2.3 Engine knock question?????

1997 900s 98k I just purchased yesterday with very loud engine knock. Still runs but sounds terminal. Parts car????? Or worth engine work???? I paid 400.00. I do all my own work and like to tinker on cars. Not familiar with saab engines YET.... 2.3 liter. What should I be checking to determine where knock is from and what steps to take next.

Thanks to all for this site......

and my other 97 900s 247k I still drive daily and love it!!!!!
 

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Welcome to the forum!

I see you have the 2.3 liter. The naturally aspirated saab engines did not have direct ignition systems. Only the turbo cars do. Your car has the standard distributor ignition system, so no need to worry about a tow in the middle of nowhere :) In terms of the engine knock, are you saying its knocking like it is running on low grade gas? Please describe the knock you are hearing in more detail.
 

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Discussion Starter · #3 ·
The engine knock is very loud. Sounds like hammering inside.

The car came from a mechanic who was going to thow a used motor in it to turn a quick buck. I am trying to figure out if it can be fixed without a transplant. He did not look into the noise just was going to replace motor and sell it.



My first thoughts are to check valves. It sounds as if the noise is comming from the top end of the engine. I see the valve cover has been off recently becuase of the new gasket sealant. So I kind of asumed it is not a stuck valve but I will check first....

Is it worth messing with????

The local junk yard has an engine for 600.00 "TMU"
 

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Hmm...thats an interesting situation. Are you sure the knocking isn't from stuck lifters? If the oil in the car was not changed regularly there could be a lot of sludge in there blocking lifters, even valves. If you are good with head work, you could just do a head rebuild, although 600 bucks for a used engine is a pretty good deal. Its up to you if you want to spend the time rebuilding the head or if you wanna just get that used engine and swap it. Best of luck!

Lawrence
 

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Discussion Starter · #5 ·
Stuck lifters?????

I removed the lifters and some move free up and down and some seem stuck with little movement. ??????? What is the norm??????

And can I fix without buying new lifters

It is obvious previous owner did not do regular oil changes.......

thankyou
 

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Your action will depend on what this car will be used for..

A main bearing knock is loud, ominous and very rare
Excessive valve lash is more of a little tap tap tap..
I would pull the pack, tear her down and report any excessive wear. This should be interesting as a report on the value of changing oil.
I'd hate to see the oil screen..
I do wonder why the mechanic sold the car to you and for so little. I think he could have earned at least several hundred plus all his labor at $50 per.
 

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Well if you say some of the lifters dont even move much then thats probably one of your main concerns. The lifters job is to actuate the valves so if some are stuck then you indeed might either just have to replace the lifters or look for valve damage. If get everything to run well, I would suggest running the car on auto rx for a while to clean up the sludge and varnish that has surely accumulated in your engine. Hope it goes well.
 

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Discussion Starter · #8 ·
Head is off

Removed Head today and clearly a one piston is hitting the head, I noticed wear marks evident on top of piston when comming in contact with the head.

That is the noise....... Or at least some of it.

Next I will attempt to remove oil pan and remove bad piston.......

I will look on this site now for oil pan removal.

Any tips will be appeciated....

Valves look OK
 

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I've only heard of interference between pistons and valves due to errant timing (broken belt or chain). Can you provide pictures of what the piston and head look like? This might help someone else down the road...

If that's the case, then one of the valve stems might be bent. At any rate, it's definitely worth taking them out to check. In fact, since the head's off ou might as well take off the manifolds and port match them!
 

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I had to replace mine on the old 94. 99 is fine, although relatively young @ just over 50,000 miles.

I think it's a crap shoot, some will never break, some will break 7 times.
 

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Discussion Starter · #11 · (Edited)
Head and Piston Photo's

This is what I found #3 piston comming in contact with head. Can see wear marks on top and bottom edges of piston and slightly on head. No apparent contact with valves?????

I am going to attemp oil pan removal today......It sounds like fun....
And then remove # 3 piston.

Pan is out. Conecting Rod BEARINGS SHOT!!!

Sump screen plugged........

Thanks Everyone for all info..... Looks like it needs a motor transplant.
 

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Could you tell us how the removal of the oil pan and sump went? Anything to look for when removing? How difficult? Thanks
 

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Discussion Starter · #13 ·
Timmay said:
Could you tell us how the removal of the oil pan and sump went? Anything to look for when removing? How difficult? Thanks
I search this site under "oilpan" before I began and found some great info.

my car is a 2.3

I found it not hard at all. I have a car lift and air tools. If you have these availble it is about an hour + job.

Basically I remove the exhaust. I followed the wires comming from exhaust piece and undid the quick connect wire plugs. This looked easier than trying to mess with the sensors on the exhaust pipe. Both connect on the top right side of engine on a bracket near carb. The Back wire had no wire clips, the front wire on exhaust had 3 metal clips, 2 wire clamps on front of engine.

Next removed nuts on rear engine mount and supported engine. I used a floor jack and a 2by6 piece wood I had. Just for support.


Then removed sub frame bolts on pas. side (3) and just loosend on Driv. side.(3)most of the way
I used IMPACT gun and got all but one out and had to heat last one with torch.

I was able then to remove all oil pan bolts. I raised the engine slightly with the jack I supported it with I was able to remove PAN....

In the pan remove sump shield and sump pickup "they are torx head".

Now I have to do my other Saab of the same year.........

If anyone is in question of the sevice history for their car I would say this needs to be done.


Good Luck All

IMAD
 
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