Any high-mileage Supercharged 3.4L owners out there??
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gamefreakgc
Elite Member
I think basically everyone who's driven a SC'd 4Runner thinks this same way. Toyota was a little too conservative on power when they designed this engine. But then again, they were coming from that slug of a V6 the 3VZ-E. I hated that engine.
I had 221k miles of Supercharged fun on my engine before it blew. Not the supercharger's fault though.
volkinator
New member
Put mine on at 210k after purchasing it with 200k. Came out of an 01 with about 60k on the SC that I could guess at least.
Compression test tells lots. If your numbers are good, go for it. I did all the other maintenance I could while in there. Valve cover gaskets, PCV valve, etc
gamefreakgc
Elite Member
Rings would be a bit too much. The biggest thing is to make sure your fuel system and ignition is up to the task. Make sure you have the right plugs and new wires if old/unknown. Make sure you have optimum fuel flow so an injector service of some sort, even if it's just multiple bottles of injector cleaners will help. Also replace the fuel filter if it's never been done.
Gaskets are not a big deal, the only two gaskets that will see boost pressure is the lower intake manifold gaskets (these are stout) and the head gasket, which handles boost fine.
Bennythbeaver
New member
204k on my rig with supercharger. installed at around 197k. no 7th inj but did
have to change out knock sensors. Also sent off the injectors to witchhunter
for cleaning, glad i did cause 4 of the 6 were not in good order. Runs way better
now and no issues.
have to change out knock sensors. Also sent off the injectors to witchhunter
for cleaning, glad i did cause 4 of the 6 were not in good order. Runs way better
now and no issues.
seen20
New member
1997 Tacoma SX v6 5sp TRD supercharged 300HP Methanol Injection, Reg Cab 620,000 miles Build thread | Tacoma World
Dude had the supercharger on since new and the 3.4 made it till 489k miles before it blew a head gasket.
Dude had the supercharger on since new and the 3.4 made it till 489k miles before it blew a head gasket.
I have a touch under 250k on my 4Runner, and it's been supercharged for every single mile, ever since 1999 as it was a dealer option. No drivability problems whatsoever, I finally pulled it off to send in for a rebuild preemptively as it wasn't really making odd noise and the nose cone spins very easily and quietly. Only issue is the O rings in the bypass tube stopped sealing and created a vacuum leak that was quickly fixed with some RTV.
NegroTundra
New member
Bump. I have a 98 with 280k that I'm itching to bolt on the new Magnuson TVS1320. Seems counterintuitive to bolt on a potential issue to a motor that has been so good over the years. But damn, I'm hungry!
Devbot
New member
I've been thinking the same for a while and tbh it's just not a good idea. When I was looking up some accounts of people supercharging around the 300k mark I found some guy that added one between 300-350k and it didn't even last a year before it blew his head gaskets
If you did head gaskets recently it might hold up a little better, but that also means the next weak link would be at risk, which would likely be piston rings or valvetrain. A compression test would give you a better idea on how strong those still are, but wouldn't tell you how much longer the trans will last from the major increase in hp/torque (don't forget a 7th injector is very commonly needed just to avoid pinging at lower elevations which would only boost the numbers higher)
People like to say "well you can always just take it off" but that doesn't do you very much good once the engine's been damaged or you've burnt up a gear in the trans
Ultimately it's your vehicle and your money but personally I find it to be extremely risky
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NegroTundra
New member
How are we to arrive at the conclusion that the SC was the reason for his HG fail? At this mileage, it seems that is risk with or without.
Good call on the compression test though, maybe I'll start there as a general health checkup. I have a TRD second gen SC on my auto trans garage queen, and since I live at elevation I've never needed extra fuel mods or otherwise and never experienced pinging. This higher mileage mountain beater is a manual, so I'd like to think trans may hold up a bit better, though it is due for a clutch.
Will continue to ponder. It is a lot of $$ to throw into an old rig.
Devbot
New member
There isn't any outright definitive reason to know/discern it was; however blowing head gaskets with forced induction is extremely common due to increased pressure in the combustion chamber the heads+studs were never meant to see - which is heavily exacerbated by both old, tired gaskets and engines that were designed to be low compression, such as the 5VZ - not to mention radically increased temps which have a similar effect. Detonation doesn't help either. And while they're all meant to go sooner or later, with all that information in mind one could readily deduce (or at least make a reasonable assumption) that, at the very least, it was prematurely hastened along by adding a blower at such a late stage in it's life. For other examples you can look at nearly any NA engine that people turbocharge and attempt to run tons of boost through - head gaskets are most frequently the first to go
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