Mechanic Fixed Head Gasket, At Completion Tells Me I May Require Engine Rebuild

[80 Life]

I have heard a tons of mixed opinions on replacment motors. Many people have told me a 93' or 94' engine is required for my 93' Cruiser.
Recently I was told that a 95'-97' is a straight swap into a 93" Cruiser, but that a 93'-94" cannot be swapped the other way into a newer 95'-97'.
Any thoughts on this?

 

[Malleus]

The early engines used VAF instead of the MAF the later engines used, so that won't be a plug and play installation. You lose the PAIR system if you install the later engine in the early models, so that has to be accounted for. All this can be done, but it's not plug and play. It may be easier to install a later engine in an early model than the other way around, but ...

The lower end of the engines are the same, so if your plan is to keep your head and install a new lower end, yes, that will work. But it's no different from doing the same thing with an early engine.

 

[use2bn83]

The early engines used VAF instead of the MAF the later engines used, so that won't be a plug and play installation. You lose the PAIR system if you install the later engine in the early models, so that has to be accounted for. All this can be done, but it's not plug and play. It may be easier to install a later engine in an early model than the other way around, but ...

The lower end of the engines are the same, so if your plan is to keep your head and install a new lower end, yes, that will work. But it's no different from doing the same thing with an early engine.

The bottom end is a bit different if you’re looking to swap a used short block in. The later models have a reluctor on the crank for the crankshaft position sensor. I reckon they use a different oil pump drive gear to make room for the reluctor on the late models that way they can use the same balancer. And an upper oil pan with a provision for a crankshaft position sensor.

As far as going one way or the other. The long block is backwards compatible from 95-97 to 93-94 and is very straight forward. There are some head differences, but all of the ancillary accessories and manifolds can and should be reused from your truck.

 

[tmxmotorsports]

I'm kinda in the same boat but have a 95 with big hole in oil pan piston decided it wanted to come out the bottom. Have a complete 94 engine out of an 80 I'm ls swapping has a bad miss more than likely head gasket. Looking to swap a engine into the 95 but don't want to have to switch a bunch of stuff around so I'm going to hold off on putting the 94 engine in. This thread has been a roller-coaster...

 

[Malleus]

Just to be clear, the crank position sensor in the newer engines wouldn't pose a problem for installation in to the older model 80, as long as the original distributor was used (item 4):

Same for the two piece oil pan in the newer engine: you'd use the earlier engine's oil pan, so it doesn't matter. What does matter is the connection to the ECU (item 2).
1993-1994:

1995-1997:

the harnesses aren't compatible. I haven't compared the ECU's, but I suspect they aren't either, since they use different protocols.

 

[Malleus]

It's entirely possible that the thyristor (or whatever's on the boards) is the same, or similar enough, so that the connectors can be swapped and the ECU would notice the difference. Again, I'm not saying it can't be done, just that it's not "unplug this engine and plug that one in".

I do know (because I've been working on an OBDI cable lately) that the DLC 1 connector is grounded direclty on the VAF on the early models and the MAF is grounded through the engine harness, which accounts for the discontinuity between the terminals on the MAF connector housing, so that's another wiring conundrum that has to be resolved. I haven't heard anyone describe the details of how that's to be done, as of yet.

From the 1995 EWD (E2 is the MAF ground) (1993-1994 is as above, E1 is the DLC 1 ground):

 

[use2bn83]

It's entirely possible that the thyristor (or whatever's on the boards) is the same, or similar enough, so that the connectors can be swapped and the ECU would notice the difference. Again, I'm not saying it can't be done, just that it's not "unplug this engine and plug that one in".

I do know (because I've been working on an OBDI cable lately) that the DLC 1 connector is grounded direclty on the VAF on the early models and the MAF is grounded through the engine harness, which accounts for the discontinuity between the terminals on the MAF connector housing, so that's another wiring conundrum that has to be resolved. I haven't heard anyone describe the details of how that's to be done, as of yet.

From the 1995 EWD (E2 is the MAF ground) (1993-1994 is as above, E1 is the DLC 1 ground):
View attachment 3265857

Absolutely correct and good info. The harnesses and ecu’s are not compatible and many of the accessories as you’ve pointed out. One would simply want to use the long block and the 93-94 accessories etc

 

[slow95z]

I have a couple of OBD1 engines if you are down for going to used route. Would recommend taking that clean new head of yours and putting it on the good bottom end though

 

[80 Life]

I have a couple of OBD1 engines if you are down for going to used route. Would recommend taking that clean new head of yours and putting it on the good bottom end though

I messaged you. Thanks

 

[JoeCova]

Here are some videos I got.

Engine at idle, (Drivers side, Passenger Side, Center)


Engine with rev. (Drivers Side)


Cold Start RPM's. Jumps to 1500 RPM's in park when cold. Drops back down when thrown in park.
Cold Start RPM's - https://youtube.com/shorts/wVjDuKyh1ks?feature=share

Warm Motor RPM's. Sits at 800 RPM's once warm in park.
Warm Motor RPM's - https://youtube.com/shorts/o2l-H-Nwq9s?feature=share

This sounds like a rod bearing knock. My engine sounded very very similar but the only way to verify truly is to tear the engine down. Mine had minor scoring on the bearing and crank, probably could have lasted a long time like that but would eventually fail. I ended getting a new shortblock from Toyota and rebuilding the engine.

EDIT: Saw you confirmed it was rod bearing knock, wish I saw this thread earlier but seemed pretty straightforward.

EDIT2: I'll have a rebuilt shortblock soon that I won't need.

 

[80 Life]

This sounds like a rod bearing knock. My engine sounded very very similar but the only way to verify truly is to tear the engine down. Mine had minor scoring on the bearing and crank, probably could have lasted a long time like that but would eventually fail. I ended getting a new shortblock from Toyota and rebuilding the engine.

EDIT: Saw you confirmed it was rod bearing knock, wish I saw this thread earlier but seemed pretty straightforward.

EDIT2: I'll have a rebuilt shortblock soon that I won't need.

Messaged you.

 

[60 toy ota]

another way to confirm the rod knock (especially if it's really bad) is to get the cylinder in question to TDC and then ~1/2 way on the down stroke (so that the connecting rod is near vertical). then gently place a long piece of wood or something through the spark plug hole till it softly comes into contact with the piston. Finally, give it a good shove and listen/feel for the knock.

So was this approach to diagnosing used? If so, did it reveal anything?

 

[80 Life]

So was this approach to diagnosing used? If so, did it reveal anything?

This was not done. You had said this was more useful with really bad knocks, but everyone who hears this doesn't even think its a knock at first so I would not call it a bad knock.

 

[80 Life]

Ordered a new shortblock from Olathe Toyota last night. Was told today it would arrive in 4-6 weeks, I was expecting to hear 4-6 months.

Below are the options I saw to getting back to smooth running.
1) - I was told rebuild could get as high as $10,000 with my original motor due to unforeseen things that may show up once inside the motor.
2) - I was offered a motor for $6k fully rebuilt but that doesn't include any warranty so I can't find a shop to install it. After $2-3k for install I would be near that $10k mark anyways if I found the right shop.
3) - I looked into running swaps, but paying $1k for the motor and $2-3K for install is too pricey to get something older and tired put in. In the short-term its the cheapest option, but probably the worst solution in the long-term.
4) - Shortblock came out to $4100 after taxes and shipping. This takes away so many unforeseen issues that can happen during rebuild. I am expecting to put my refreshed top-end on the brand new shortblock. Should save a ton on parts and I am guessing labor will be around $3k. Hoping to get this done for under $8k total.

 

[tmxmotorsports]

I would say that's the best way to go about this if funds are available...

 

[codgn]

I went through the same thing a couple years ago. My engine had really low compression in all cylinders. Short block in my opinion was the best way to go! I ordered mine from olathe as well and after a ton of new parts and having the cylinder head done and have my buddy help me it came out around 6500 dollars or so

 

[codgn]

If you need a extra set of hands or need a case of beer let me know! Im over in Aurora

 

[Fj80oregon]

Hopefully they ship it in that time frame many members here have heard that same song and waited months. Glad you got a game plan figured out. Make sure your mechanic measures your head bolts to FSM spec when installing. They are torque to yield and stretch and have been torqued multiple times now. Most would recommend to replace or use ARP head studs at this point. Have you found a shop yet to do the swap?

 

[80 Life]

If you need a extra set of hands or need a case of beer let me know! Im over in Aurora

Super appreciated. This is a job I am going to leave to the shop.
Same goes to you if you ever need a hand. I don't know much, but an extra hand can go far when working on the 80's.

 

[80 Life]

Hopefully they ship it in that time frame many members here have heard that same song and waited months. Glad you got a game plan figured out. Make sure your mechanic measures your head bolts to FSM spec when installing. They are torque to yield and stretch and have been torqued multiple times now. Most would recommend to replace or use ARP head studs at this point. Have you found a shop yet to do the swap?

I found a shop up in Loveland, Colorado that was recommended to me by the Slee guys. Seems like they do a lot of engine rebuilds and prefer to work on older Toyotas.
I am sure I will end up waiting months for the new short block. The only short block in stock in all of America is in Medford, Oregon but they don't ship.

Edit: I do have new ARP studs that were put on a few months back when I got the head work done.

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