• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Lower End appears to have seized.. now what to do?

T

tomr

New member
I have a 2001 Grand Prix GT L36 with 158k. Recently, cruising at 60mph the motor just quit, no major noise, poor performance or indication of trouble beforehand, acted just like you had turned off the key. Could not get it to crank or turn over, battery was fine, no charging system issues. Towed it to my mechanic and it appears the motor has seized (breaker bar cannot turn the crank). Now earlier at 133k it burned a valve, since the body / interior were very clean and the trans was rebuilt at 110k, I went ahead and replaced the rear head and had a valve job on the other one. My experience with other high mileage 3.8L and 3.1L based GM cars lead me to think their lower ends were pretty reliable.

Anyway I do need to verify the mechanics findings but my first thought was to find a shortblock and transfer my fairly new upper end. Most of the other postings here appear to be against going the rebuild route. Thoughts?
 


I would ask your mechanic to make sure the motor isn't hydrolocked.
If he pulled the plugs and the engine doesn't move in either direction then it is seized.
 
I bought mine from ebay. Went the full boat by getting the GM ESI dvd. It's everything anyone could ever want. If paper is more your thing, you should also be able to find the full GM manuals for just your car on ebay as well by searching for the year/model and Service manual. It's usually 2-3 books
 


BillBoost37 said:
I bought mine from ebay. Went the full boat by getting the GM ESI dvd. It's everything anyone could ever want. If paper is more your thing, you should also be able to find the full GM manuals for just your car on ebay as well by searching for the year/model and Service manual. It's usually 2-3 books
Click to expand...

UPDATE: Finally the mechanic had the time to look at this, pulled the plugs and it is not a hydrolock problem. He says that even with the plugs out the crank will not turn in either direction with a breaker bar. I plan to dig into it further myself. Plan is to get a better idea of what is the issue is before pulling the motor.

So what are the other possibilities, albeit remote, besides a crank issue, spun main bearing, main bearing cap failure? Looking at what is attached to the crank you have

Timing chain
Flywheel
Rods

BTW how difficult is to remove the timing chain cover or drop the oil pan on this model? Thanks
 
You have to remove the nuts on the motor mount, jack the motor up and remove the u-bracket from the engine and then you can drop the pan. Also remove the oil level sensor from the side of the pan so it doesn't catch on the pickup tube.

Not sure on the front cover.
 
if it locked up, just get a used engine, you'll spend more money trying to rebuild it then its worth really.

after you find a new to you engine, you can take the old one apart to find out what went wrong, if you even care at that point.
 
scottydoggs said:
if it locked up, just get a used engine, you'll spend more money trying to rebuild it then its worth really.

after you find a new to you engine, you can take the old one apart to find out what went wrong, if you even care at that point.
Click to expand...

X2 If it is seized then it's seized and there is nothing you could do to make it worth fixing.
 
Did you have the upper intake manifold checked? For awhile the 3.8 had a problem with the stovepipe for the EGR and the plastic intake. Basically it would over time cause the plastic to turn to mush and finally let coolant into the intake and eventually enter the oil pan and size the bearings.
 


carpart.com morads. craigslist part outs. junk yards.

being your N/A you should have no problem finding another engine. there are a ton of cars with the same engine in it. new or old you can swap some of your old parts, like mounts and such so it fits right.
 
Since you are NA.. lookup say 2007 NA GP engines. Here they are very cheap with low miles. Put on your UIM and fuel rails and off you go.

As far as locked up. Here's my take. You can pull the engine and trans together then pull the trans off and fight the engine on the hoist to unlock it to get your converter off. (engine has to turn to get converter) Or for $100 you simply get a new converter, fresh engine and poof.. you're back in action.
 
BillBoost37 said:
Since you are NA.. lookup say 2007 NA GP engines. Here they are very cheap with low miles. Put on your UIM and fuel rails and off you go.

As far as locked up. Here's my take. You can pull the engine and trans together then pull the trans off and fight the engine on the hoist to unlock it to get your converter off. (engine has to turn to get converter) Or for $100 you simply get a new converter, fresh engine and poof.. you're back in action.
Click to expand...

@ BillBoost37 Thanks, searching for a used L26 yielded a better selection. Looks like these models used them



Now you mentioned in a previous thread
---
L26'ing requires a TB adapter, different intake and a pcv hose where you likely drill/tap the TB. Not horrible, but more than some want to do.
---
So are there modifications to deal with using the original UIM to circumvent ? Thanks again
 


If you swap the UIM, TB and fuel rails over. The only other modification you might have is the oil pan mount. The 04+ GP has a little bracket 10345562 ~$13 that the engine mount bolts onto. If the engine comes with the bracket/mount you are read to drop in. If not..either buy one or grind the big U shaped mount bracket a little to clear the aluminum oil pan.

IMG_5065.jpg

IMG_5098.jpg


Personally I love the aluminum pan/mount. If you ever did a gasket on the pan..it's super easy to get the mount and pan off.

If you get a lucerne engine, you'll need to change the oil filter adapter with yours as that car puts the filter in a slightly different angle that would hit the subframe.

Other than that..swap your rear exhaust manifold onto the motor and you would be ready to drop it in.
 
Thanks for the info. Good stuff. Searching for 3800s in 2007 I see there is a "2" and a "4" for the 8th digit on the VIN for these motors, what is the difference
3.8L, (VIN 2, 6-231)
3.8L, (VIN 4, 6-231)

Thanks
 
being that your going to have to swap some small parts from your engine to the donor engine, i dont think it will matter. go for the one with low miles. if you can check out the rocker arms to see if they are clean or caked with burnt oil, that little peek tells you if the last owner changed the oil regularly. ( just open the oil fill cap and look inside.)
 
You must log in or register to reply here.
Back
Top