99 5VZ-FE Head Gasket Tacoma

New member, checked forum 15 minutes, decided to go ahead and post my questions. I AM IN MEXICO RIGHT NOW. After a check engine light came on, here is what my mechanic has replaced. Coil, plugs, wires. Then cleaned injectors. None of it solved the chugging, low power. He says we are down to a head gasket replacement. Let's stop here. I've researched head gasket kits and timing belt kits, and shipping from the U.S. to Mexico. I know about YotaShop for head gasket kit, and Aisin for water pump, and Mitsubishi for timing belt. Now, can anyone add some advice, or warnings, or anything? Gotta get this resolved soon as possible. Thanks.

 

What trouble code did your mechanic pull?

 

did he check compression?

 

current mileage on the odometer?
AT or MT?
sorta sim sit going on here right now at 356k miles and i am clueless what is going on
my engine burns no oil and coolant level never noticeable dissipates
and seems to only happen after a time spent on the road after 50, 100+ miles it loses pep but no CEL is triggered

is this your situation currently? other than the CEL being triggered

 

O.K. Thanks all. Here's what I know. The instrument he used showed I think a prob w cyl 5 which made him think it was a coil or a plug. I said coil so that's what the did. No success, so I said change out the plugs. The plugs had a red cast to them meaning they were hot. He and another mechanic thought that could be water in the gas, so I ran the gas out, put in fresh high octane. No luck, still chugged. Next changed out wires. No change. Next took out injectors and cleaned them (outside shop). No change. Next compression check. This showed compression bad in one cylinder, but then it sorta moved around a bit, the bad compression reading showing up elsewhere. This made him think the head gasket is bad, that somehow the bad gasket shifts a bit, causing a different cylinder to show bad compression. That is sorta where we are. I'm going to call him and tell him I am buying my kits from the States, so just quote me labor. I'm going to find out if he's done this work before w the gaskets. I am ordering the timing belt and water pump kit too, and will have that done. What are your thoughts now? I see gasket kits that seem to include everything but the kitchen sink incl valve gaskets and wonder how deep should I go with the gasket replacement. The truck is a 99 3.4L manual transmission 4x4 with only 145,000 miles, but it's been in Mexico a lotta years and could have had bad gasoline. However, it was in the U.S. the last 3 years. I changed out every conceivable fluid and belt except timing belt 2 years ago. Timing belt was changed out 60,000 miles ago so I don't mind changing it out now since the engine will be opened anyway to get to it. What are thoughts about what you all would do re gasket replacement, just the head gasket? Any other advice, all appreciated. Thanks.

 

Heads (and the block) will need to be checked for straightness.

 

Is that a visual check for straightness or does it require a tool or instrument? Thx.

 

Get a machinist straight edge and a set of feeler gauges, then check to the spec listed in the FSM. Use the cross-box method for checking flatness.

 

From ~4.40 mark:

 

OK, for all those still hanging in there. I took the 99 Tacoma V6 to a different mechanic, someone who has done head gasket replacements, a 50 something mechanic for a lot of years, in SoCal and here in MX, someone who gets a lot of praise around here. He checked it and said he thinks it is not a head gasket problem, so he thought about what it could be. Knowing plugs, wires, coil replaced, injectors cleaned, engine not overheating. ----- Tonight he said compression is 110 which he thought is not terrible, but the engine is still misfiring. He took off the intake manifold thinking it must be injector 4 needing replacement, or it's a valve out of adjustment. Injector 4 checked out ok and the valves checked out o.k. ------------ I told him maybe think about for a couple days what else it could be. He said he'd do some research on everything that could cause a misfiring engine, running rough, besides everything we've tried. Normally, he said, a misfire is something pretty quickly solved. Here I am, 145,000 miles on a 5VZ-FE 99 Tacoma I've owned for 18-plus years. Any thoughts he might look into? Thanks.

 

Have you ruled out bad gas and/or clogged fuel filter?

 

Bad gas, yes, running high octane from good source.
Fuel Filter!!! -- Thanks. Will mention it to the mechanic.

 

Thanks to everyone. Mechanic took his time, and over the weekend thought about it. I Whatsapped him every conceivable idea from Internet including from this forum. Apparently he decided to return to the injectors and go back through them, even though they'd been sent out to be cleaned. He called me late Friday and said he was almost 100% sure that injector no. 4 was not functioning properly. I had him order it in, and it was installed. 99 Tacoma now running as it should, after several weeks of trial and error. What a good feeling that is. Some mechanics have a knack or a patience or apply both and don't give up. God bless 'em.