Thoughts when considering a JDM Engine

Vehicle: 3.4L Tacoma 2WD
Mileage: 226,000
Automatic Transmission: Shifts Great

A persistent engine tap is helping me make a decision about whether to replace or try to get the short block overhauled locally. Inspections for noisy valves and rod bearings have not produced problems in those areas. This looks like a case of one or more bad wrist pins.

I appreciate Hotdog11's post about things to consider with a JDM engine. Since I plan to do most of the work myself, a JDM might be the best route for me. I will go into detail after this quote.

1) There is a JDM seller in Memphis that I would use. They list engines for ~$1,100. Using this seller will knock $100 off the shipping cost. So the delivered price will be ~$1,300. If something goes wrong and I need to return it, I know people in Memphis who will tell me where they live.

2) When the engine is delivered, I will put it on an engine stand in the garage and go to work. I will run a leak down compression test to look for bad rings or valves.

3) Front and rear main seals and any rubber hoses, VC grommets, and related gaskets will be replaced.

4) The timing belt, water pump, and any related wear items will be replaced with new.

5) Rod and main bearings will be removed and inspected. If they are not perfect, they will be replaced.

6) I will install new throttle body, intake and exhaust manifold gaskets. The current intake will be moved to the new engine.

7) Sensors will be moved and most likely replaced.

8) Injectors will be sent for cleaning and flow rate testing.

I think I will benefit from the JDM engine's A/C compressor, alternator, and PS pump. The current A/C compressor is seized up. I can get the alternator tested. The P/S pump will need to be inspected.

I noticed the current engine has two hoses that route through the short block on the oil filter side. The current hoses do not appear to go anywhere. I have not seen outlets for those hoses on JDM engine pictures. I may be missing something.

The oil filter will be relocated from the JDM location. Though, from what I see, I prefer the filter JDM location if it will work.

What else should I consider before jumping into this project?

In looking over the current engine, I suspect it was damaged from severe overheating. I can see where the previous owner replaced the heads. The rod bearings do not look like they have 226,000 miles. Though, I did not see any evidence of the oil pan being removed in the past 100,000 miles. It had too much grime build up for it to have been removed in the past 10 years.

Pictures of the heads and lower end are listed below.

Head


Lower End

 

the two hoses are for coolant flow to and from the engine oil cooler. If your "new" motor doesnt have them and your old one does then you need to put on the correct water pump for use with and engine oil cooler. Verify the rib count on the pulleys and accessories before you install the motor. The only other thing I can think of is make a list of seals and such and order them in advance... my Toyota dealers parts shop is small and most things have to be ordered. Kind of frustrating wanting to do something and cant for lack of a $10 bit that is dealer only.

 

Thank you for the tip. This pump is listed for use without the oil cooler.

https://www.rockauto.com/en/moreinfo.php?pk=949003&cc=1357589&jsn=390

 

If you are going to take the whole bottom end of the JDM apart anyway, why not take apart the motor you have and rebuild it yourself? Is it a question of the time without your truck?

 

It's weighing heavily in my decision. I would like to keep the swap time to a minimum.

 

Keep in mind that mine DID NOT come with the AC compressor or the starter. About the only two things that were removed. I don’t know if that’s consistent or just on mine.

 

From my research when I was considering the same thing I found that often times high mileage 3.4 engines have cracked heads. They seem to be able to run for years like that, but when it comes time to rebuild, often one or both heads will need replacing. When I was pricing out a rebuild, the cost to replace the heads alone totaled more than an entire JDM. That was the breaking point for my decision. If you've got the time and energy, I'd suggest pulling your heads and have them checked out at a machine shop. If they can be resurfaced then go for the rebuild. If not, it quickly becomes a money pit.

 

there sure seems to be a rash of people suspecting wrist pins or talking about them right now.

Is this someting to do with climate change?

Toyotas are not known for this even after overheating.

Are ya'll finding rocking pistons or loose rods leading to this diagnosis? Our engines have loud ticks even when doing fine.

edit: I sure would think a broken piston (really, what;s failing with the pin?) would hit a valve and MAKE it's presence known.

 

Figuring the average jdm motor has less than 50k on it, most of the things on your check and replace list is overkill. I wouldn't buy a truck with 30k on gthe clock and then strip the engine down. It would waste of time money and resources. And tbh unless you've done it a few times you're running the risk of taking a perfectly good engine and making it a needed rebuild. Any average engine in the last 20 years should roll 200k without issue.

The last engine I did shipped with 0 accessories, don't anticipate getting a free alternator. And double check hose routing, oil pan shape and other bits that might cause interference. Many engines from the other side of the ocean are configured a bit different.

 

A JDM motor is a total gamble roll of the dice. You have NO idea how many miles it has or if it’s a 1995 motor or a 2004 motor. Less than 50k is all BS with ZERO documentation. These motors are 20 years old now. There are plenty of JDM motors that are sold that are junk and plenty that are good.
You can google people that have bought bad JDM motors. If your doing the work and the motor is bad
it will not cost you anything but time. If you have a shop do it your out 1500.00 for labor and the possibility of another bad motor. That’s 1500 x2=3000.00 if you get a bad motor which is very possible.

My motor popped a head gasket at 480,000 miles. It didn’t burn ANY oil.
Was cheaper to replace it with a used motor with 100k miles for 1500.00
then to fix the head gaskets. The mechanic took the engine apart just for curiosity
and everything inside the motor was tight and normal wear even at 480k except for the head gaskets. So in reality the JDM motor migh have 200k or more miles
and because these motors run forever no one would know otherwise.

Either way I would replace as much as you can with the motor out of the truck. Transmission front and rear seal, transfer case seal front and rear. Clutch if applied.
Knock sensors and knock sensor wire harness and the coolant pipe gaskets by the knock sensors too. Valve cover gaskets and timing stuff.
It’s so easy to do these things with the motor out of the truck.
If you want headers now is the time for them if you decide too.
I believe the pulleys are different and the oil pan is different too.

Good luck if you go JDM
Personally for the amount of work involved I would find a running motor that you
can hear and inspect in a truck and have a carfax to know the miles and maintenance.
That way at least you have some idea of what your buying instead of zero info

 

Just from looking through the engine, it looks like the heads, radiator, timing belt, and possibly the water pump was replaced 3,000 miles ago. There must have been some catastrophic failure and overheating that caused it to require all of that maintenance at once. I think they were trying to fix the tapping noise and gave up.

 

One note about used replacement engines, there is an LKQ store a few miles from my place. I know several mechanics in the area that purchase used LKQ transmissions and engines. So I've seen a lot of go jobs go with LQK engines. Though, I know I can be burned. For whatever reason, there seems to be a number of 3.4L engines from Minnesota. No idea what happened to the donor trucks.

 

I did this with mine. Got a JDM engine and replaced pretty much everything. I posted some pics and detail in this thread post #3:

https://www.tacomaworld.com/threads/engine-swap-project.569291/#post-19031168

 

To add:

I had to...
1) move the dipstick from the side of the block to the front timing cover by removing the plug in the cover and JB welded it in to the block dipstick hole
2) use my exhaust manifold as the JDM was a diff angle
3) use my old intake manifold (diff angle)
4) use my old fuel lines (intake manifold different)
5) use my old wiring harness
6) use my old A/C bracket (JDM one was slightly different)

Most things I replaced are listed in the thread I linked above

 

Great work! You've got a nice shop. I actually have an engine hoist, transmission jack, large truck jack stands, impact wrenches, and bunch of tools that all fit the Taco. I've done my share of serious engine work for a DIYer. I've been ambivalent about jumping into this engine job. I have a lot of house projects to do between now and summer will take priority. Lots of work to do to free up one of my garage bays and get organized for this type of job. The time of year that I like to do this work is in September/October.

Also, I've been preoccupied with fixing the cowl leak for the past few days. Once I see that issue fixed and get it back on the road, I will be in better spirits for engine repair.

In the meantime, I've been thinking about running the Rotella 15w40 for diesel engines to see if it helps. I might put a Diesel decal on the front fenders as a joke until I can remedy the tapping noise. Ha!

 

I've got a jdm in mine...the guy had to do a little switching of parts from old to new. I have logged 80k plus on mine since the install with zero issues.

 

Just to report on my progress. I purchased an LKQ engine from a Florida 1 Owner 1998 4Runner with 70,000 miles.

The vehicle was rear-ended on February 22, 2019, and declared a total loss on March 12, 2019. The vehicle was scrapped on April 16, 2019. This is a recent salvage.

I got to see pictures of the car, the speedometer, and the accident damage. Also, I have service records where the car was put into service in Orland FL, and serviced at https://www.centralfloridatoyota.com/ The vehicle has only lived in FL since it was new. The CarFax shows the previous owner frequented https://www.centralfloridatoyota.com/ for service.

With LKQ I opted for the 6-month parts and labor warranty for $253.05.

The engine price was $1,687.00.

 

This is the only way to do it in my opinion!! I did the same thing when I replaced my motor at 480,000 with a 2004 motor.

 

BTW while I’m thinking about it, make sure you intstall a TOYOTA pilot bearing NOT an aftermarket bearing.

This is what the aftermarket bearing did to my output shaft of my transmission 90,000 miles later. Pretty much destroyed the end of it

 

Thanks for the tip. Both donor and receiver are automatics. I'm familiar with replacing pilot bearings on manual clutch jobs and using bread to remove it. ;-)