Mystery....Need engine experts.

[gamefreakgc]

Aww that's a real bummer. Head gaskets are starting to get more common as these engines age more and more. Not as bad as 2nd gens, that's for sure, but still becoming an issue. However, $2600 one sure does beat a car payment every month for the next 10 years. Besides, there's talk of another corona cash hand out from the gov't...

 

[994wd]

Did it slowly get worse? I sometimes get a little bit of shaking ish from my motor when I idle it for a little while most of the time after driving a lot. I haven't done any of my plugs/wires/coils yet so I'm hoping it's just that. I also have a 99 with 160k currently.

 

[Former_Jeeper]

Yep it slowly got worse no codes, no noticeable coolant level change really either.

I did all the plugs wires iacv, pcv etc.......but in the end obviously it didn’t help bc it was coolant seeping in causing a rough idle.

I’m hesitant to spend this much money on it but I guess I’ll commit to keeping it going. Let’s just hope this isn’t the start of a money pit.

Hopefully your issue is something cheaper but ............sounds like a HG

 

[phattyduck]

Aww that's a real bummer. Head gaskets are starting to get more common as these engines age more and more. Not as bad as 2nd gens, that's for sure, but still becoming an issue.

I think too many people neglect their cooling systems, which leads to the head gaskets going bad from the coolant side in to the cylinder. (not counting the early 5vz gaskets/engines with the known issue) My mind could be changed with some other evidence though...

-Charlie

 

[Gull81]

I think too many people neglect their cooling systems, which leads to the head gaskets going bad from the coolant side in to the cylinder. (not counting the early 5vz gaskets/engines with the known issue) My mind could be changed with some other evidence though...

-Charlie

Which 5vz have a faulty gasket? I have a 1997 and a head gasket issue is the last thing I want in my life right now.

 

[phattyduck]

Which 5vz have a faulty gasket? I have a 1997 and a head gasket issue is the last thing I want in my life right now.

'96's and maybe early 97's. Heck, it may have already been done on your truck if the recall applied.

-Charlie

 

[plcfcng]

Any of the 5vz can have head gasket failure I have a 2001 that I replaced a head gasket I did one on a 98 and a 97. I think the head gasket will fail at some time at about 220,000 give or take 20,000 your mileage may vary. The only thing you can do keep the cooling system serviced when it does happen take care of it right a way it will only get worse. Don't wait you will end up overheating the engine causing more damage. The JDM engine is a way to go but that can be a crap shoot. If it's only a head gasket I would not go the JDM route but I would make sure I get the heads resurfaced and the valves cut.:guitar2:

 

[Thebeastlives]

Any of the 5vz can have head gasket failure I have a 2001 that I replaced a head gasket I did one on a 98 and a 97. I think the head gasket will fail at some time at about 220,000 give or take 20,000 your mileage may vary. The only thing you can do keep the cooling system serviced when it does happen take care of it right a way it will only get worse. Don't wait you will end up overheating the engine causing more damage. The JDM engine is a way to go but that can be a crap shoot. If it's only a head gasket I would not go the JDM route but I would make sure I get the heads resurfaced and the valves cut.:guitar2:

Totally agree with your statement as the motor ages a head gasket can happen and chances are it will happen. I had 1 blow on my 96 3rd gen at 300k and my son had 1 blow on his 4th 08 at 270k. Even the 4.7 v8 have them blow on their 4 runners or lexus when miles get up there. I've always maintained my motors and radiators but age and miles cause even Toyotas to break sometimes.

 

[Majkmichael]

Ok so about a month ago the 4runner (99 3.4L Auto 150k) started shaking really bad but only at startup and only for about 10-15 seconds. So naturally as a somewhat mechanically inclined person I

Cleaned MAF sensor, replaced air filter, Replaced IACV valve, cleaned throttle body, replaced PCV valve, grommet, and hose. Replaced spark plugs with Proper OEM as well as NGK wires.

Shake did not go away as i thought it would. No codes have been thrown during this mystery also. Once the shaking stops it is smooth as butter for the remainder of the drive.

Fuel filter is relatively new. All 02 sensors are newish and proper Denso units.

I have used propane to search for vacuum leaks and did not find any, replaced some vacuum hoses as well (just to be anal).

Some of you have no doubt concluded maybe a headgasket. However, oil looks clean and radiator is full, no smoke or sweet smell out of the tailpipe.

So now I am stumped. Hopefully I missed something small that someone else can help me solve this mystery as I am about ready to take to a shop so they can charge me a ton of money only to replace stuff that doesnt need replaced and not fix the problem lol.

Thanks in advance.

Drive around for about 20 minutes then squeeze the upper radiator hose, if it feels like it pushes in at all you have a head gasket issue. I know you said you're not losing coolant but the tiniest little leak will cause it to run rough without showing a loss of coolant.

 

[19963.4lsr5]

Every 4Runner I bought had a dead rad cap and wouldn’t let it build pressure.

However, saying that if you don’t have a overheating problem you could drive with the cap loose and see if it acts differently.

If lack of pressure makes it better you have a head gasket problem.


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