3.4 toyota sludge prone or no?

[Ben99GT]

Originally Posted By: TheKracken
Originally Posted By: Nick1994
Not sludge, but I think the 3.4L is known to blow head gaskets. So maybe coolant is getting into the oil and sludging?
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3vz fe (3.0) is known to blow head gaskets. Not the 3.4 (5vz fe). Absolutely amazing motor and pretty easy to work on. Doesn't mean its not possible but not a known issue.

OP, if you want to run the oil 8-10k go for it. I am sure the oil is good for it. I personally run 5k OCI on my 3.4 but it is not rusting to [censored] and I plan to own it for a long while.


The 3.4 5VZ-FE had head gasket issues. In fact, my Dad had a 1995 T100 with the 5VZ-FE that had the head gaskets replaced under a Toyota special service campaign.

Good engine, but no, not exempt from head gasket problems.

 

[02SE]

There was a Headgasket recall on early build 5VZ-FE's. From inception to early '97 build dates. I have a '97 4Runner which I bought new. It is the oldest vehicle I own. I recall receiving the recall notice, but my 4Runner was built in July of '97, and they had already fixed the issue on the assembly line by that point in time, so my 4Runner didn't fall into the category of affected vehicles.

20+ years later, it has no sludge, no rust (despite being used on heavily salted roads every winter), no Headgasket issues, and runs and nearly looks like the day I drove it home. It has required ONE repair in it's 20+ years of use. A hydraulic clutch hose, which cost about $20.00 and a half hour of my time to replace.

Regarding the valve cover gaskets: Usually the valve cover bolts can be GENTLY tightened to stop any seepage. The torque spec is 4.3 lb-ft IIRC. Lots of people get carried away and apply WAAAY too much torque to those bolts, and end up stripping threads or cracking the valve cover around the bolt holes.

Maintain them and wash any highly corrosive chemicals (like Salt) off them as necessary, and they can last a very long time.

 

[jongies3]

You're thinking of the 3.0 that had sludge issues due to head gasket problems that precedented the 3.4 you currently have. For that long of a run, you're better off using a quality synthetic that'll help clean up the engine in the process. The 3.4 is a excellent engine, I've never had a lick of trouble with mine, other than preventive maintenance like timing belt. I run syn and change every 7500 miles or 6 months, whichever comes first. It had a lot of varnish when I got it but after several runs on synthetic I can see it's a lot cleaner inside so that makes me feel better. How many miles does it have on it?

 

[spencerdiesel]

I've been thinking, I do some pretty short shifting for fuel economy and take hills in the highest gear I can. Is a xw30 weight oil good enough do y'all think? I'd have no problem trying a 40 weight oil, other than couldnt that offset some of the mpg? Thoughts welcome

 

[TheKracken]

Ive run 0w20 in the 3.4 toyota no problem. A 5w30 would be just fine, the truck specs 30wt anyway....

As for mpg, it will help but you won't noice the improvement from tank to tank, pretty hard to detect the slight increase.

 

[spencerdiesel]

Good deal! What conventional 5w30 oils are on the thinner side at operating temp?