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Anyone had 3.0 to 3.4L engine swap done? Problems, benefits?

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We have a '93 Itasca Spirit with rear dinette, really happy with it size-wise, layout-wise, and personality-wise, but the 3.0 has a weak cylinder, probably a burnt valve.  Head gasket was done by Toyota at 75k, it now has 90+k, and it's passed its last CA smog inspection.  So we have about a year and a half to fix it.  I read here of ToyOnly swaps in Oregon, and contacted them.  They do the swap with a used but good 3.4L, all modifications and new timing belt etc.  


Their customers seem happy, but with such a major modification, I know we have to deal with CA DMV, and that's OK, I figured on that.  But I wondered if anyone here has had that done, and were there any resulting issues, or was it all smooth sailing?  More power, better mileage (than our 5 1/2 cyl current engine), and it sounds great, but as a lifelong mechanic, I know there are plenty of things that can go wrong.  I no longer want to do major engine work, and want something we can enjoy for a while til we're too old, so getting another smooth 50k miles out of it would be fine.


In the past, I'd probably have pulled the heads and done the work, even though I can see it's a miserable engine to work on.  But I'm debating, if I take it into a shop, they do the valves and heads, and timing belt etc., and we can get another 50k out of it, that might be acceptable too.  Even paying a shop, the price would be less than half of the conversion, though the cost is secondary.  Primary is that I want it reliable, and no 'clunk clunk' as you go down the road because the 3.4 engine bangs into the wheelwell, or other unforseen glitches.


So if you've had this done, or know of someone who has, any advice or info would be appreciated.  We're on the shop's waiting list, and will probably go ahead with the swap unless it's a mixed bag of benefits and we may be better off just fixing the 3.0.

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Before you consider the swap you must contact the California bureau of auto repair for instructions. Helps to have the vin number of the vehicle the engine came out of. My daughter is a manager at DMV and even she didn't know all the rules. Helps to actively work with a referee during the swap

Engine Changes - Bureau of Automotive Repair (ca.gov)

You will have to have it inspected by the referee after the change. 

Linda S

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That's helpful...though apparently they locate an engine just before starting the process (or they say they can get low mileage Japan engines for additional cost).  So I couldn't give them the VIN in advance of paying the deposit.  ToyOnly says they'll use a CA vehicle for all the needed equipment, but it's "our responsibility" to deal with CA smog.


I didn't know about contacting the DMV BEFORE proceeding, but it sounds like I'd better do that.  I knew about the referee inspection but thought if it passed the emissions test and had all the original CA smog equipment from the new engine, and the two catalytic converters from our current one, it would be OK.


Contacting the DMV may influence my decision, if it's too big a hassle...a valve job on the current engine wouldn't require any of that, so I'll see what they say.


I know ToyOnly has done CA vehicles before, and according to the customer's facebook posts, they've passed smog, but I have no idea how much hassle they had to go through beforehand.


Thanks for the info, it might save me from a big hassle later.

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I'm a pretty advanced hobbyist and have done swaps, as well as full engine rebuilds.  A burnt valve is pretty minor in the scheme of things and at only 90k miles odds are good the rest of the block is fine and ready to go another 100k.  Your background probably tells you the same thing.  


I'd personally find a used engine and swap the heads, doing some head prep in advance to make them ready - valve guides, valve grind, etc.   Then simply swap the heads in a couple weekend wrenching sessions and you're good to go. 


On swaps, they always seem to end up MUCH more expensive, and create issues of their own.  Is the cooling system plumbing lining up?  You need a new engine computer, different wiring harnesses, does the cruise control no longer work, the exhaust will be custom, the motor mounts will be custom and possibly create vibrations from then on no matter what you do (mounts are custom from the factory for an engine family...), etc.  So I'm not a fan of swaps.


So, I'd be a fan of simply taking care of the head(s) and moving on with a stock and predictable vehicle.  YMMV...

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Thanks IdahoDoug, I think the reason I posted hear was that somewhere in my head was the nagging knowledge that such a major swap might be just creating headaches (and more so with CA emission issues possibly complicating things) .


They gave me a pretty thorough list of what's needed, and it's a lot...steering box, hood scoop, lots more, in order for the 3.4 to fit properly, but with so many changes, I agree that there's a lot to go wrong, or at least bring up new problems.  They do convert the cruise control and A/C, of course at extra cost.


It IS almost tempting to dive into it myself and do the heads and timing belt; just looking under the hood, seeing everything packed in there so tightly made me decide I wasn't going to tackle it myself (getting up in years and lazier 8^).  I'm not familiar with this particular engine as it hasn't needed any work up until now, but I do have the PDF manual so maybe I'll look it over and see if I'm tempted.


 It runs great (though I can hear the weak cylinder at idle), no oil use, no leaks, no sign of coolant problems/leaks, trans oil looks clean and smells fine.  It's drivable now but won't pass the next CA smog test.  Maybe it doesn't make much sense to do such a major undertaking for a somewhat minor issue.  I know the 3.0 isn't a well-liked engine, perhaps that influenced my thinking on it too.


Appreciate the info, this board and its members are a great asset for keeping these great little motorhomes on the road.

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