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Motor Swap Issues

6K views 60 replies 10 participants last post by  mrwiggles2004 
#1 ·
Hey guys, it has been quite a while but it's good to be back!

I am in need of some guidance regarding a recent engine swap in my 97 bird.

The back story:

It has been quite a while since I have posted, mostly due to the fact that my motor exploded roughly 6 years ago. Since then the car has been parked in a garage in Alabama, basically untouched. I had some spare time this past week with the 4th Holiday to begin swapping over the transplant engine which I acquired roughly 2 years ago.

Details on the donor motor:

'02 mustang GT 4.6L, purchased from Craigslist. By all accounts looks clean inside and out. All T-bird specific parts required have been changed out. Mounts, oil pan, pickup tube, flex plate, etc.

Issue I am having:

After swapping the old motor for the new, I have come to the point where the engine is mated to the trans, and all bolts have been snugged. The crank pulley will not rotate at the point where I am applying more torque than I am comfortable with on the crank pulley bolt. If I unbolt the motor from the trans and back it off about a half inch I can rotate the motor easily with a breaker bar, and can also easily manipulate the torque converter. Mate them back, and no movement. Additionally, with everything bolted up there are not enough threads exposed at the TC to get the nut on. I can get a regular nut started that does not have the offset threads of the factory nut. My thoughts are maybe the nuts need to be on the TC enough to pull the TC forward because it's pushed back and binding on the housing.

If anyone has experienced a similar issue, or can provide any insight it would be greatly appreciated.
 
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#2 · (Edited)
NO! There should be no pulling of the TC forward when you tighten the nuts, they should be sticking out of the flex plate with the converter 100% seated in the Trans (and be sure that it is).

You say this engine came from an 02 Mustang GT, was it an auto or a 5 speed? If the latter I'd suspect you left the clutch pilot bearing in the crank, preventing the converter from seating.
 
#4 ·
Thank you for the swift responses.

You are exactly right, and I can't believe I did not check that. That is 100% what the issue is.

At this point the motor has to come back out, and the TC is likely toast. Any recommendations on an upgraded replacement? I don't want to pile a ton of work on myself, but if there is a direct swap that is an upgrade I would like to spring for it.
 
#5 ·
Mark VIII/Marauder/Mach1 TC is a direct swap, slightly higher stall speed, and dirt cheap. They're also smaller diameter and won't balloon.
 
#8 ·
Great info, and ideas.

So, after removing the manual bearing is there a replacement bearing that needs to go in the crank for the auto trans, or does the TC just mate up directly?
 
#10 ·
Awesome, thanks for your help Matt.
 
#11 ·
#13 ·
How far did you get before realizing the issue? Did you fully torque the trans to the motor, and if so was there any damage to the torque converter when you separated them?
 
#15 ·
I wanted to provide a quick update on the issue I was having and my progress. Once I got the motor back out, I looked and the throw out bearing was indeed there. Knocked the bearing out using the bread and socket method. Put the motor back in, buttoned everything up, and she runs! I drove her 231 miles from South AL to Atlanta yesterday with no major issues.

One thing I am running in to is that the new motor does not seem to have a temp. sending unit for the temp. gauge. or maybe it is just that I can't find it. Has anyone who has done a late model 4.6 PI swap run in to this issue? and if so how did you mount the second sensor? I have seen people run a T fitting off of the ECT temp unit hole and mount both sensors on the same hole, but I would like to avoid going this route if possible.

Thanks in advance.
 
#18 ·
I appreciate the replies, that's what I figured. For those of you that have drilled and tapped the crossover, has anyone done it with the intake in the car? I would think the intake would need to be out to keep metal shavings from getting in the coolant passages.
 
#19 ·
Intake has to be out or else you will destroy the water pump for sure. It's aluminum so you can't use a magnet to pick up chips either. Some people install a inline temp adapter on the radiator hoses for gauges. Best bet since the ECU is already getting the temp from where it wants. The gauge is bonus.
 
#20 ·
Hey Guys,

I have some bad news, and wanted to get some advice on next steps with the car/motor. I got the car running with the new motor and had been driving it for a bit before things started to go south. The car had plenty of power and was by all accounts very strong right after the swap. Eventually it began to develop a rough idle, loss of power and misfire in cylinders 1 and 4 according to my scanner. I racked my brain and replaced and checked all of the obvious culprits. What I eventually ended up finding, once I pulled the valve covers, was three rocker arms had popped off and they were laying in the head, and one of the intake valves was stuck in the closed position and the spring, retainer and locks had all popped off. No sign of the locks, assuming they ended back up in the oil pan, since while the car was running rough, there were no indications that there were issues with the bottom end. Since then I have replaced the hydraulic lifters and rockers for those three valves and got the spring retainer, and new locks back on to the one valve. It appears to be completely stuck because when I attempt to rotate the motor by hand the back of the valve stem wants to slip off of the back of the rocker arm once it gets to the point where the cam lobe would start pushing it down.

I do not see any way around pulling the head at this point and at the very least having the valve guides, and valves looked at by a machine shop. My question is what could have caused this? I don't want to go through the trouble of pulling everything apart and putting it back together only for this to happen again because it is the symptom of some other issue. My immediate thoughts are oil starvation could have cased this, or the previous owner (Mustang guy) did god knows what to this thing before he decided to ditch it. Any help or insight here is much appreciated.
 
#21 ·
The only thing that does that is the pistons hitting the valves.

I did that at high RPMs, about 7000, but it was only one valve.

It sounds to me like whoever put the cam in did not check for piston to valve clearance; the chains are loose at startup, until the oil pressure comes up, so that's probably when they hit.

This is the first time I've heard of this particular problem.

If the valve is moving sideways, the guide is cracked or worn badly.

I'd pull that motor, and go over everything carefully; you could have broken chain guides or something.

The heads have to be reworked at a minimum; the valves are probably bent, and at least one guide is bad.

Do a teardown, and post pix.

There will be marks in the carbon on top of the pistons, showing what happened.
 
#22 ·
Thanks Grog, that was my initial thought as well. PTV contact or loss of oil pressure. There is no side to side play in the valve, it's in there very tight. Tight enough that it will not budge. It is possible that this was not a factory cam and it was installed incorrectly. Aside from giving everything a visual inspection, I put the motor in as it was from the original seller, so no clue if the cam was factory PI or not. I'm going to start tearing in to it this weekend, and will post up some pics after.
 
#23 ·
I was looking at the cams listed in your sig; Comp XE268's.

Loss of oil pressure will either cause the rods to knock/seize, or the cams to seize; Cams break chains if they seize.

Valves only fail like that if they hit something.
 
#24 ·
Ahh, got it. I need to update my signature. Those cams were in the original motor, but when it blew I essentially replaced it with what I thought was a stock '02 Mustang GT motor. Update: I got the top end off and I am close to having the front cover off as well. The timing chain going to the head with the stuck valves is extremely loose, I suspect what I will find when I get the cover off is either a failed tensioner or broken guides. Either way I will get some photos up of the results. Taking my time here, but hoping to have more info this weekend.
 
#25 ·
Here is what I found when I finally got the timing cover off this weekend... Looks like the passenger side tensioner has failed. It also looked like the guides were toast on that side as well. Next step is to get the head off and over to a machine shop for new valves, guides and seals for the three that were damaged. Anyone have any ideas as to what could have caused this? Also, I was under the impression that the 02 and 0 GT's came with the plastic tensioners without the ratchet system, which leads me to believe that the previous owner may have replaced these in the past.

36903
36904
36905
 
#26 ·
The 03 cars definitely had plastic.
36906
 
#27 ·
Update: I got the passenger side head off this afternoon, and was a bit surprised to not see any PTV contact on the pistons. I ran the car for a while after the issue started so it's possible that all of the un-combusted fuel had washed off the marks. Anyways, after I got the head to the machine shop they determined that 3 of the intake valves and guides were bad (I am assuming this means bent, but I didn't ask the tech to elaborate) I should have the head back on Thursday and will start getting things put back together, hopefully before it starts getting colder.
 
#28 ·
Alright, I have the head back on and torqued down. I made sure to put the head on with the pistons down to avoid PTV contact when putting them on. My next challenge is timing the pistons/cams since I have pulled the whole thing apart. From what I can gather I need to pull the cams off, and set the #1 piston to TDC, and from there the cams should go back on with the timing marks in the 12 o'clock position, and from there I line up all of the timing marks with the chain end links. My question is, how do I know if the engine is in the intake or exhaust stroke for TDC? Does it matter since the ECU is using the cam sprocket as a reference does it automatically know?
 
#29 ·
You’re way overthinking it. Simply lay the chains flat and Mark the links at each end that are vertical, and just line the marked links up with the crank sprocket dot (at TDC) and the cam sprocket dots. Dot to dot, simple as that.

You can do this with the cams loose but I prefer to have the followers removed. Then just rotate the crank with the keyway facing straight left or right where all pistons aren’t at TDC and pop the followers back in with a screwdriver.
 
#30 ·
I'm sure I am. Just don't want to tear back in to this thing once I get it back together. Do all followers need to be removed or just the intake side?
 
#32 ·
Got it. Thanks for the help, I'm going to give it a shot this afternoon.
 
#33 ·
Update: I got everything lined up this afternoon. Marked timing chain end links, with crank timing gear at 6 o'clock lined up the cam timing marks on both with the end links and timing mark on crank gear with other side. Released the tensioners. I start rotating the engine by hand to make sure nothing is binding, and I get to roughly half a rotation (timing mark at 12 o'clock, keyway at around 4-5) before things bind up. FYI, all spark plugs are out. I am pretty well stumped at this point. Any ideas what I could have done wrong here, or why things could be binding up?
 
#34 ·
Take a pic with it together, get the chain marks in the pix. :)

This is a stock PI motor, correct?

You want to turn it over, by hand, at least 4 times with the spark plugs out, to make sure nothing is touching anywhere.
If you get the marks lined up, it should be fine, but I always do this for a new engine.
I do it with the front cover off, so I can see the tensioners drip oil, and makes sure oil is getting to the top of the engine..

If you feel any tightness, figure out why before you hit the starter.

EDIT: I walked away to deal with cat issues, and just saw your post.

Pop the chains back off, yank the followers, line it all up again, and post pix of the cam and crank, with the chains at the marks.
 
#35 ·
Stock PI motor. Passenger side head was replaced with a remanufactured unit after it was trashed in earlier part of this post, aside from that everything is 100% stock. I'll take a few pics of it tomorrow and post up with the timing marks shown. It was dark when I got it all back together this afternoon. Timing mark on crank is at 6 and both cam gears are close to 12 respectively with the end links lined up on the timing marks. There is only one timing mark on the front of the crank gear correct, and both cam chains line up to the same mark?
 
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