A poll if you changed to synthetic Oil And if you have had gaskets leaking with the 3.4 v6 motor

Because I’m considering changing to Synthetic Oil because it’s a better oil, I though I would do a poll to see for those that have if there have been new oil leaks from the synthetic oil on the 3.4 v6 motor.

I know there are plenty of tests that say synthetic will not cause an older engine to leak,
But there are plenty that say it will.
(Not including the valve gaskets because they give out around 150-200k)

Hopefully a poll will give some more real numbers with the 3.4 v6 that are pushing 20 some years old now.

 

I use a blend, 5w30
And yes currently I have a bit of vcg leakage.
(They all will?)
due to age and prior unknowns, cannot say for certain.

 

Valve covers are a given with the 3.4 at about every 150,000 or so but oil pan and rear main seal and cam seals would be very expensive to do.

 

My rear main leaks if I run 100% synthetic oil.

 

Seriously!

 

Older seals can do that. When I switched back to a blend it stopped.

 

That would destroy my clutch if that happened,
Good to know

 

It can if it leaks long enough without being fixed.

 

I bought my truck with 68,000 miles on it. I have used the following on every oil change since.

Mobile 1 Synthetic High Milage 5w30
Lucas Oil Stabilizer High Milage Synthetic
K&N oil filter


My valve covers started to leak at around 230,000 miles: have since been replaced.

My rear main seal (was not leaking) was replaced when I swapped in the A340F transmission during my 4wd swap.

My truck does not leak or use any oil what so ever... I'm now at 330,000 miles.

 

Oil pan should be simple to replace.

Your cam seals should be replaced with your valve covers anyway.

Rear main could be expensive if you don't do it yourself.


Edit... Correction... Your cam seals should be replaced with timing belt. Cam plugs are with valve covers.

 

No leaks w/ newer VC gaskets. (5-6yrs.) Next clutch will get a main seal, needed or not. It's just time.

 

semi synthetic

 

Engine can't tell the difference whatever motor oil is used or what you started with. I now save a little going with a blend. Don't know where I erred about keeping with synthetic and thinking I had to keep with it. Bunk rumors no doubt. I'm almost broke and change the oil in my truck once a year now. I don't use regular oil, I use a blend.

 

My 2001 has 81k miles & I just switched to Pennzoil Platinum high mileage full synthetic 3 weeks ago or so. Put around 500 miles on it since then so not very many. No leaks yet but probably to early to tell.

 

I switched to Valvoline Maxlife at around 200,000 mi and I didn't have any leaks afterwards. I'm somewhere over 245,000 now. In the past year I developed a leaky VC gasket. The VC gaskets have never been replaced. I've tightened the bolts I could access and that seems to have bought me some time till I can do the job.

 

I got my 2002 taco with 32,000 miles in 2007 and have used full synthetic ever since. Just a little leak around the valve covers which is normal. I have 190,000 miles now. I switched all the fluids over the year I got it.