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MDH33
11-20-2013, 01:58 PM
Anyone with a 5VZFE had the timing belt slip? If so, what were the symptoms?

My dad has a 4runner and just had the timing belt done and it was running fine then suddenly made a noise, started running badly, missing, etc. He took it to the shop that did the belt and they said no compression on #1. :confused: My guess was the belt failed, but the compression thing has me confused.

nakman
11-20-2013, 02:18 PM
if the timing is off, then the exhaust valves could be opening up too early? But why would that just be on one cylinder. Just a guess obviously.

On one of the Tacos we owned when I had the timing belt done the shop said my old one was off by a tooth. I didn't notice a difference though, after they corrected that.

AxleIke
11-20-2013, 04:12 PM
if the timing is off, then the exhaust valves could be opening up too early? But why would that just be on one cylinder. Just a guess obviously.

On one of the Tacos we owned when I had the timing belt done the shop said my old one was off by a tooth. I didn't notice a difference though, after they corrected that.

^ That'd be my guess on the compression. Robbie, Squishy or thefatkid will hopefully chime in.

I'd guess they mucked up the tensioner. Never had that happen in any of the 5vz trucks (fam has 4 of them). Did they do anything else while they were in there?

powderpig
11-20-2013, 04:23 PM
All the shop needs to do is remove the plastic covers to see if the cam's are timed right. Should not be a real big thing. If the cams are not timed right, they would of found the problem. Wonder why they made the choice to check compression? seems like a waste of time, unless they already pulled the plastic covers to inspect the cam timing.

MDH33
11-20-2013, 05:57 PM
All the shop needs to do is remove the plastic covers to see if the cam's are timed right. Should not be a real big thing. If the cams are not timed right, they would of found the problem. Wonder why they made the choice to check compression? seems like a waste of time, unless they already pulled the plastic covers to inspect the cam timing.

Yeah, not sure why they checked the compression either, which made me suspicious. I told him to call back and confirm they checked the timing belt. I also said it might be worth taking it to another shop. (He's in Michigan).

Would the timing belt failing or slipping cause a compression issue?

DaveInDenver
11-21-2013, 06:15 AM
Yeah, not sure why they checked the compression either, which made me suspicious. I told him to call back and confirm they checked the timing belt. I also said it might be worth taking it to another shop. (He's in Michigan).

Would the timing belt failing or slipping cause a compression issue?
Yes. If the cam timing is wrong the valves are opening at the wrong time in the cycle and yields low or zero compression. Not sure checking the compression is any easier than just inspecting the timing belt on a 5VZ, but it's a valid check for a slipped belt or chain. If the mechanic works on lots of brands he may not be super familiar with the 5VZ, though, and sometimes a compression check is actually easier. If it broke the engine wouldn't run at all, I'd guess Isaac is probably right about the tensioner if all that was done was a belt and maybe water pump.

MDH33
11-22-2013, 08:42 AM
So, the shop pulled the oil pan and the #1 rod is broken... Engine is toast and it only has 92,000 miles on it. :mad: I feel like such a chump because I talked my dad into buying this thing and raved about how reliable these 3.4's are.... His first Toyota (and his last I'm sure).

Anyone have a good 3.4 for sale?

DaveInDenver
11-22-2013, 09:03 AM
Wow, that's not encouraging to hear. Do you know any history on the engine?

MDH33
11-22-2013, 09:09 AM
Wow, that's not encouraging to hear. Do you know any history on the engine?

Not really. He bought it last year from a dealer. No warranty. I was skeptical of the low mileage but it looked pretty immaculate. Carfax seemed to corroborate the mileage.

If no one has a good 3.4, any suggestions/recommendation on where to get a rebuilt short block?

nakman
11-22-2013, 09:22 AM
Broken connecting rod? that seems almost unheard of.. dang, sorry Martin. too bad he's not closer, he could borrow the 3.4 that's down the street for a bit while you sort this out ;)

Squishy!
11-22-2013, 09:22 AM
I would talk to Jim's Got Parts for a good deal or Central Foreign Auto for a good lower mileage long block. I paid 1200 5 years ago for a 90,000 mile motor that's still running a blower @ 10psi. Don't be discouraged, there are thousands of happy 3.4 owners for every mishap like yours. This kind of thing happens. Keep us posted on progress and let me know if you need help and I'll do what I can.

MountainGoat
11-22-2013, 09:40 AM
:( If it's any consolation my 2000 4Runners have 240k and 300k. Both 5VZFE motors are tighter than the 1FZFE in my 80 with 290k.

rover67
11-22-2013, 09:57 AM
so.....

ALL the valves are still in their normal locations?

like it really did break a rod and it wasn't a valve that got munched due to botched timing belt/tensioner breaking a rod?

AxleIke
11-22-2013, 09:59 AM
5vz is non interference. It won't munch the valves if you screw up the belt, it'll just run like crap.

Major bummer about the broken rod. Should be able to find another motor on short order. Where does your dad live?

MDH33
11-22-2013, 10:28 AM
Thanks the tips and consolation guys. :o

He's in Detroit. Sounds like he found a 98,000 replacement and they're going to swap it in and do the timing belt, waterpump, some gaskets, etc. I told him to get under that thing and get a good look at the rod. I want to know where and how it broke. There was no indication on the top side looking into the cylinder with a camera that there was damage, so that's why they pulled the pan, apparently.

The shop is recommending the replacement engine rather than just a new rod because they think there might be fragments throughout. Sounds plausible?

rover67
11-22-2013, 10:37 AM
Where in Detroit? I'll be there next week.

DaveInDenver
11-22-2013, 10:45 AM
so.....

ALL the valves are still in their normal locations?

like it really did break a rod and it wasn't a valve that got munched due to botched timing belt/tensioner breaking a rod?
Isaac already mentioned that it's a non-interference motor but I was more wondering if the engine happened to maybe have any head gasket work or something. A broken rod is unheard-of even for supercharged 5VZs and crazy for a stock engine. Maybe it threw a rod and something was lost in translation. That can happen (right Ige?).

The best way I can think to break a rod is to get oil, coolant or water in the combustion chamber. Maybe HG? Is it running Toyota red coolant or does it have something else? I have a theory that Toyota coolant reduces HG erosion but worse is mixing coolants.

I would go with a decent used engine instead of just replacing the rod in situ. That worked in the 2F but modern engines are such close tolerances and designed with a lot less margin. When the rod broke who knows how badly the crank or cylinder walls were damaged. At least my luck wouldn't be in favor of tempting Murphy.

wesintl
11-22-2013, 12:25 PM
Where in Detroit? I'll be there next week.

8 mile

MDH33
11-22-2013, 01:29 PM
Where in Detroit? I'll be there next week.

What the heck are you going there for Marco? I didn't think there were any businesses left to bring anyone there for work. :o

8 mile

Good guess actually. That's where the family business has been since the 60's.


Seriously though, he has the Runner at a shop in Pontiac, which is about 30 minutes from downtown D-Town.

Opie
11-22-2013, 03:29 PM
Sucks about your Dad's 4Runner, Martin. A friend of mine is from Detroit, with roots in the auto business. She's not allowed to even consider owning anything other than American. Hopefully your dad will give it another go. Sounds like a freak occurrence.

Your post had me dig up the history of the VZ engines. Fascinating... http://en.wikipedia.org/wiki/Toyota_VZ_engine

p.s. check your pm's when you have a minute.

AxleIke
11-22-2013, 03:45 PM
Isaac already mentioned that it's a non-interference motor but I was more wondering if the engine happened to maybe have any head gasket work or something. A broken rod is unheard-of even for supercharged 5VZs and crazy for a stock engine. Maybe it threw a rod and something was lost in translation. That can happen (right Ige?).

The best way I can think to break a rod is to get oil, coolant or water in the combustion chamber. Maybe HG? Is it running Toyota red coolant or does it have something else? I have a theory that Toyota coolant reduces HG erosion but worse is mixing coolants.

I would go with a decent used engine instead of just replacing the rod in situ. That worked in the 2F but modern engines are such close tolerances and designed with a lot less margin. When the rod broke who knows how badly the crank or cylinder walls were damaged. At least my luck wouldn't be in favor of tempting Murphy.


Well, the SC adds a bit of a twist, but yeah, a stocker shouldn't have have had anything. People do bend rods in SC'd trucks because the SC gives the engine enough low end grunt that you can practically start the thing in 5th gear on a hill. The rods are the weak link and will bend if you don't run in a low enough gear.

I think we have to keep in mind that the reliability of Toyota's is because of the sheer number of cars out there they make that run and run and run forever with little to no problems. But, the law of large numbers says that they'll still have a few that are total junk boxes.

If the rod actually snapped, I'd guess it was just a casting flaw and it finally gave out.

Dave's idea about the HG is a good one. It doesn't have to even get oil or coolant in there. I rebuilt the top end of a 3.0, which did the engine wonders....until the increased compression caused the thing to throw a rod and it died a noisy death on the side of the road.

HOWEVER, I doubt that in this case. The 3.0 had nearly 300k on it. The compression was WAY low and the thing blew a head gasket. This engine sounds too young for that to happen.