1985 2.8 knocking

sdimewisher · 09-22-2009, 01:26 AM

ok..I just scored a 1985 4wd blazer for 200 bux..only catch is that there is a small rod knock.

my question is:

can I pull the oil pan off with the engine still in the truck?

If not, what do I need to do in order to pull the pan off?

Im planning on pulling the pan, and putting in new rod bearings to see if its just a bad bearing...if not, im swapping engines....

I was also told that 1985 was notorious for cracking cranks.....any truth??

I can get a 89 camaro 2.8 to swap in for fairly cheap....what do I need to do to swap in the camaro engine. I know its mpi and my truck is carb'd. can I just swap intakes, and oil pans/pumps?

I just sold my 93 with the 4.3, so the 2.8 is a whole new ballgame for me

neo71665 · 09-22-2009, 01:46 AM

Gonna have to pull the engine unless you figure out something I aint.

Anything 85 and before had smaller mains and its said they are bad about cracking cranks.

To put the 89 f-body engine in all you do is use your intake and oil pan/pump.

Shaggem · 09-22-2009, 08:42 PM

neo is right on pulling the engine out. 85 2.8's had lots of problems with cranks due to the main journal size and some balancing issues. if your truck has a mechanical pump which I think but not sure 85 model did and the 89 camaro block has that portion of the block blocked off. you will need an inline electric fuel pump and dont ever reuse an used oil pump. buy a new one for the year of the vehicle you are swapping into. you will need to strip the donor engine down to the long block and use the 85's valve covers, intake/carb, exhaust, sensors, 87 or later s10 flywheel and balance, pulleys, accessories, front timing cover, oil pan and like I said before purcahse a NEW oil pump pick up tube(your has shavings in it) for the 85 engine. the oil pumps are the same and you will also need the distributor off the 85 as well. I have a 87 camaro 2.8 in my 89 truck.

sdimewisher · 09-22-2009, 11:52 PM

could I thoereticly purchase a 86 2.8, and drop it in? would the 86 not have the crank issues, AND bolt right in?

neo71665 · 09-23-2009, 12:12 AM

82-85 used a v-belt set up, the front cover, and accessory drives, oil pan

86 (maybe some late 85s) had a combo v-belt and serpentine belt, front cover very specific, oil pan

87-93 had all serpentine belt dive, front cover, oil pan

I forgot about the oil pan being year/front cover specific. You can still use the 89 motor you just have to use front cover, oil pan, intake, and exhaust manifolds off your truck on it. I'm trying to remember but I'm almost sure the 85 had a mechanical fuel pump and you'll have to change to an electric one is you use any block 86+ (the improved blocks). Swapping everything over really aint that hard and gives you a good excuse to change the timing chain.

Shaggem · 09-23-2009, 02:49 PM

do yourself a favor and soak the exhaust bolts with some penetrating oil for a few hours then spray them down again, start the truck and let it run til the exhaust is hot then shut off and the bolts should, not always, but should come out easier. or you can just use a torch to heat them up.

sdimewisher · 09-28-2009, 12:59 AM

well....I replaced the rod bearings, put fresh oil in her, and fired her up...the knock is quieter, no knock at idle, but driving, there is still a slap, slap, slap...quiet, but still there...

ddog800 · 10-20-2009, 11:47 PM

How's your timing on it? You got a timing light?

sdimewisher · 10-21-2009, 03:47 AM

havent checked the timing...engine is coming out, aand gettin rebuilt...ho hum.......

ddog800 · 10-21-2009, 12:32 PM

Quote: Originally Posted by sdimewisher

havent checked the timing...engine is coming out, aand gettin rebuilt...ho hum.......

hehehe, understood... it's a non-issue at this point then. Good luck with the rebuild!

09-22-2009, 01:26 AM	#1
sdimewisher under construction Age: 23 Join Date: Jan 2006 Posts: 138 Location: User is: OffLine	1985 2.8 knocking ok..I just scored a 1985 4wd blazer for 200 bux..only catch is that there is a small rod knock. my question is: can I pull the oil pan off with the engine still in the truck? If not, what do I need to do in order to pull the pan off? Im planning on pulling the pan, and putting in new rod bearings to see if its just a bad bearing...if not, im swapping engines.... I was also told that 1985 was notorious for cracking cranks.....any truth?? I can get a 89 camaro 2.8 to swap in for fairly cheap....what do I need to do to swap in the camaro engine. I know its mpi and my truck is carb'd. can I just swap intakes, and oil pans/pumps? I just sold my 93 with the 4.3, so the 2.8 is a whole new ballgame for me
	[Reply w/Quote]

09-22-2009, 01:46 AM	#2
neo71665 4x4 v6 blazer Age: 29 Join Date: Oct 2004 Posts: 5,006 Location: rison arkansas User is: OffLine	Re: 1985 2.8 knocking Gonna have to pull the engine unless you figure out something I aint. Anything 85 and before had smaller mains and its said they are bad about cracking cranks. To put the 89 f-body engine in all you do is use your intake and oil pan/pump.
	[Reply w/Quote]

09-22-2009, 08:42 PM	#3
Shaggem blown up .....again Age: 31 Join Date: Jul 2002 Posts: 242 Location: MO User is: OffLine	Re: 1985 2.8 knocking neo is right on pulling the engine out. 85 2.8's had lots of problems with cranks due to the main journal size and some balancing issues. if your truck has a mechanical pump which I think but not sure 85 model did and the 89 camaro block has that portion of the block blocked off. you will need an inline electric fuel pump and dont ever reuse an used oil pump. buy a new one for the year of the vehicle you are swapping into. you will need to strip the donor engine down to the long block and use the 85's valve covers, intake/carb, exhaust, sensors, 87 or later s10 flywheel and balance, pulleys, accessories, front timing cover, oil pan and like I said before purcahse a NEW oil pump pick up tube(your has shavings in it) for the 85 engine. the oil pumps are the same and you will also need the distributor off the 85 as well. I have a 87 camaro 2.8 in my 89 truck.
	[Reply w/Quote]

09-22-2009, 11:52 PM	#4
sdimewisher under construction Age: 23 Join Date: Jan 2006 Posts: 138 Location: User is: OffLine	Re: 1985 2.8 knocking could I thoereticly purchase a 86 2.8, and drop it in? would the 86 not have the crank issues, AND bolt right in?
	[Reply w/Quote]

09-23-2009, 12:12 AM	#5
neo71665 4x4 v6 blazer Age: 29 Join Date: Oct 2004 Posts: 5,006 Location: rison arkansas User is: OffLine	Re: 1985 2.8 knocking 82-85 used a v-belt set up, the front cover, and accessory drives, oil pan 86 (maybe some late 85s) had a combo v-belt and serpentine belt, front cover very specific, oil pan 87-93 had all serpentine belt dive, front cover, oil pan I forgot about the oil pan being year/front cover specific. You can still use the 89 motor you just have to use front cover, oil pan, intake, and exhaust manifolds off your truck on it. I'm trying to remember but I'm almost sure the 85 had a mechanical fuel pump and you'll have to change to an electric one is you use any block 86+ (the improved blocks). Swapping everything over really aint that hard and gives you a good excuse to change the timing chain.
	[Reply w/Quote]

09-23-2009, 02:49 PM	#6
Shaggem blown up .....again Age: 31 Join Date: Jul 2002 Posts: 242 Location: MO User is: OffLine	Re: 1985 2.8 knocking do yourself a favor and soak the exhaust bolts with some penetrating oil for a few hours then spray them down again, start the truck and let it run til the exhaust is hot then shut off and the bolts should, not always, but should come out easier. or you can just use a torch to heat them up.
	[Reply w/Quote]

09-28-2009, 12:59 AM	#7
sdimewisher under construction Age: 23 Join Date: Jan 2006 Posts: 138 Location: User is: OffLine	Re: 1985 2.8 knocking well....I replaced the rod bearings, put fresh oil in her, and fired her up...the knock is quieter, no knock at idle, but driving, there is still a slap, slap, slap...quiet, but still there...
	[Reply w/Quote]

10-20-2009, 11:47 PM	#8
ddog800 Registered User Join Date: Oct 2008 Posts: 45 Location: User is: OffLine	Re: 1985 2.8 knocking How's your timing on it? You got a timing light?
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10-21-2009, 03:47 AM	#9
sdimewisher under construction Age: 23 Join Date: Jan 2006 Posts: 138 Location: User is: OffLine	Re: 1985 2.8 knocking havent checked the timing...engine is coming out, aand gettin rebuilt...ho hum.......
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10-21-2009, 12:32 PM	#10
ddog800 Registered User Join Date: Oct 2008 Posts: 45 Location: User is: OffLine	Re: 1985 2.8 knocking Quote: Originally Posted by sdimewisher havent checked the timing...engine is coming out, aand gettin rebuilt...ho hum....... hehehe, understood... it's a non-issue at this point then. Good luck with the rebuild!
	[Reply w/Quote]