4th Gen head gaskets

[TRDCal]

There are plenty issues with prado 120 1gr. So it is common issue.

You point is irrelevant because they're both built on the same platform. Maybe it has to do with the power bump from Dual VVT-I. While the lower hp single VVT-I 1GR in the Tacoma isn't as susceptible. I don't know, I just know its not common among ALL 1GRs...if you have a better theory, by all means share it!

EDIT: This is what we get for bi*ching about MPG. Manufactures are going to great lengths to keep weight down so were bound to have a few hiccups along the way, just as you would any new product.

 

[Gumps_runner]

I had a very similar issue with rough starts & a quick vibration right after starting the vehicle. Turned out is was a very slow leak in the head gasket. it was very tricky, no over heating, no white smoke out of the tail pipe and everything ran like it should. Only thing I noticed was the coolant level was going low once a month and there was pressure building in the radiator. toyota stated bad head gasket. I replaced the entire motor, rather than a HG replacement. There is an issue with HG in there 03-05 v6 motors. There was 3 other Toyota's in the dealer getting a HG repaired while I had mine diagnosed. one was a tacoma other 2 4runners.

 

[sra2017]

4th gen head gasket

My apologies for possibly not posting this correctly but I couldn't figure out how to post this to a new thread; in brief:

- 2005 4runner SR5, 130K, all scheduled maintenance, no overheating ever, never needed to top of more then a couple of cc's of coolant
- cylinder head gasket replaced due to misfires, failed pressure tests, coolant in cylinder
- after the repair: general misfires in all cylinders, coolant loss (never occurred before), oil & coolant mixing, coolant bubbling, exhaust fumes from radiator, failed compression test on all cylinders in the driver side cylinder bank
- repair shop took it back, confirmed the above, took the head and gaskets down again and back to the machine shop, allegedly no issues with either, say they can't find a reason for the problems as head blocks and gaskets are ok (??)

1.) are there other engine related issues that may cause symptoms of failed gaskets / head blocks?
2.) how likely is the diagnosis "no issues with gaskets, heads" correct?
3.) what mistakes / errors could be committed during a head gasket replacement to cause that many engine issues?

thanks a lot if any replies and again my apologies for misposting;

 

[zonianbrat]

How much oil and coolant are mixing? Like does your engine oil look like chocolate milk? Coolant turned brown? Only a couple of reasons for a failed compression test. Good luck and keep us updated.

 

[sra2017]

Head Gasket

The engine oil is clean on the dipstick; coolant is brown from the oil, radiator full of brownish soap like liquid;

so what other reasons are there for massive coolant loss, oil in radiator and failed compression tests?

thanks again;

 

[Phils4th]

There are a lot of reasons for the problems your having. Unfortunately when a shop messes with it, you may not get the whole story or know how well the mechanic does business.

Could be:

The head surface is not straight
The head or block is cracked
The head sealing surface on the block and head was not cleaned properly
The head sealing surface is damaged
Head bolts not torqued properly or the bolts gave a false torque because the bolt holes were not cleaned.

 

[zonianbrat]

Wow, sure sounds like a mess. I guess I don't understand how the Head gaskets are supposedly ok but you have so much mixing going on. I am interested in hearing what the problem is. keep us posted.