intake manifold gasket failure

[3_puppies]

working on a customer's rig, random misfires, P0300 codes, rough idle but smooths out above idle.
nothing I'm coming up with is helping.
BIG Thanks to Paul @2001LC for some guidance, sounding like a vacumn leak.
start spraying ether trying to pinpoint a location.
seems #5 and #8 intake are leaking
get new gaskets and remove the intake
not only were both gaskets bad, 1 was installed incorrectly.
the starter was replaced by a local independent shop in Feb 2020, new gaskets were bought from a national auto parts chain, cost $29.24
I'm unsure if it is/was a quality issue or an install issue or both
sure is a nice feeling and big relief when the issue gets fixed

BUY QUALITY PARTS AND INSTALL THEM CORRECTLY!

 

[3_puppies]

a few more pics
the pics side by side is how they were installed

 

[2001LC]

Seems most work we do is correcting, what others mess up!

Proper orientation of OEM intake manifold gaskets 98-05. White tips up and out. Which gasket should always be replaced, and torque to spec, working bolts/nuts snugging in stages.

 

[3_puppies]

Seems most work we do is correcting, what others mess up!

Proper orientation of OEM intake manifold gaskets 98-05. White tips up and out. Which gasket should always be replaced, and torque to spec, working bolts/nuts snugging in stages.

View attachment 3003426

nice pic, that's what it looked like when it went back together.
I had to borrow a torque wrench from work as mine didn't go low enough.

 

[mizzle415]

nice pic, that's what it looked like when it went back together.
I had to borrow a torque wrench from work as mine didn't go low enough.

Seems most work we do is correcting, what others mess up!

Proper orientation of OEM intake manifold gaskets 98-05. White tips up and out. Which gasket should always be replaced, and torque to spec, working bolts/nuts snugging in stages.

View attachment 3003426

Just wanted to thank the OP on this diagnosis and post. I replaced the connnectors on my knock sensors after busting one off during a starter replacement several years ago when this was my DD. During connector change out I replaced the intake manifold gasket with a NAPA gasket set. After several months of running good, she started running rough and a got a host of codes indicating misfires at multiple cylinders. Did the carb cleaner spray diagnosis recommended here and saw the rpms rise.
New knock sensors and manifold gasket to proper torque, and all codes are gone and running like a champ.
Lesson learned; don’t over torque your mani gaskets.

 

[2001LC]

I've never seen, a bad factory installed intake manifold (IM) gasket(s) in the 98-05 4.7L. (Exception is the 06-07 VVT 4.7L engine, see below).

It's when someone has pulled IM in the past, we get issues.

Keys to 98-05 intake manifold gasket replacement.

1. Always clean top of engine, before beginning. Then clean gasket surfaces, until like new.
2. Always protect intake ports from dirty/dust/sand, vacuuming each port before assembly as final step.
3. Always replace gaskets, using only OEM gaskets, making sure white tip up and out.
4. Always use a torque wrench. Snugging each bolt/nut, in stages (cross or star pattern), before final torque down.

I vacuum out shop towels, which were uses as plugs in all 8 head intake ports. These helps grab/vacuum dirty in towels and around edges.

I vacuum each port of every speck of dust/sand, before assembly. Any dirt/sand dropping onto valve, stem or into head, is damaging.

Notice no gunk in intake ports of head, which I DO NOT wipe out ports to clean gunk. These are clean, because of fuel system additives (44K, Chevron Techron, SeaFoam fogger, Catoclean) used before disassembly. I was "trying" to clear CAT code, with these cleaners.

Exception:
The 06-07 (VVT engine), the factory installed IM gaskets which is rubber, do go bad (shrinks).
We've one extra KEY to a good install of these rubber IM gaskets:

1. Great care must be taken during install with these IM gaskets, which is place in IM before assembly. In that we must not bump gasket/IM on hard engine parts during assembly Doing so the rubber gets pinched between the hard surfaces, which may result in a break in rubber.

Tip:
Bend engine lift point hooks outward, before beginning. They get bent inward during install at factory. It's these we hit with IM/gasket of the VVT engine, more than any other parts of engine. I use a large crescent wrench, to bent outward!

 

[suprarx7nut]

Aftermarket gaskets are rarely a gamble worth taking, IMO. So often they're the wrong material and only "kind of" the right shape.

If there's anything you should pony up the premium $$ for OEM parts, it's gaskets.

 

[BnvS]

@suprarx7nut I'h noticed a few things actually that you want to go OEM with. Especially when the price of non oem parts are close or at times more than oem.

Like Starter, Alternator, gaskets, cv axels, cats, O2 sensors, Trans Oil (6 speed trannys), ignition coils and the list goes on...

On a side note - Ooh look at that's my 500th post. Only took me 6+ years lol. Here's to a 1000s more. God willing.

 

[excessive]

OEM or nothin'

I'll never understand why people think it's worth the gamble to save $3 on something. I used fel-pro valve cover gaskets on my 4unner a few years ago. No more than 3 years later, they failed. I had to re-do the job with OEM and no leaks unsurprisingly

 

[dealmaker]

...
Exception:
The 06-07 (VVT engine), the factory installed IM gaskets which is rubber, do go bad (shrinks).
We've one extra KEY to a good install of these rubber IM gaskets:

1. Great care must be taken during install with these IM gaskets, which is place in IM before assembly. In that we must not bump gasket/IM on hard engine parts during assembly Doing so the rubber gets pinched between the hard surfaces, which may result in a break in rubber.

View attachment 3152075


Tip:
Bend engine lift point hooks outward, before beginning. They get bent inward during install at factory. It's these we hit with IM/gasket of the VVT engine, more than any other parts of engine. I use a large crescent wrench, to bent outward!

This is exactly what I'm looking for before having starter replaced on my '06 LX470. Can you confirm the two gaskets 17171-50030 are the only gaskets I need for this job? Dealer parts dept also thought maybe 22271-50050 (Fuel Injection Throttle Body Mounting Gasket) but I haven't seen that referenced in any other 100 series starter threads, and looks like the pre VVTI 100's have diff part numbers. At only $3.68 I didn't lose sleep buying the extra gasket, just want to make sure I didn't miss any others.

 

[2001LC]

This is exactly what I'm looking for before having starter replaced on my '06 LX470. Can you confirm the two gaskets 17171-50030 are the only gaskets I need for this job? Dealer parts dept also thought maybe 22271-50050 (Fuel Injection Throttle Body Mounting Gasket) but I haven't seen that referenced in any other 100 series starter threads, and looks like the pre VVTI 100's have diff part numbers. At only $3.68 I didn't lose sleep buying the extra gasket, just want to make sure I didn't miss any others.

Yes! I'd get two 17171-50030 (IM) and one 22271-50050 (T-body) rubber gaskets. I'd always have the starter wire housing block on-hand 90980-11400 also, as the retaining clips break most times.

I'd also mod the S.A.I pump filter, or replace the pump (S.A.I blower). This is important!

S.A.I. Filter Modification, in VVT engines. To prevent its failure! Alert Alert!

We've a $2.00 part in the S.A.I. (secondary air injection) system of the VVT engine, that is taking-out ~$7,000.00 $15,000 $25,000 (inflation) in parts. WOW! I've a very easy and cheap WORK AROUND. You are going to love this ;) This thread is dedicated to the 4.7L 2UZ-fe VVT engine, in the...

forum.ih8mud.com

 

[dealmaker]

Interesting...I will peruse your thread about your SAIP filter.
I (actually a competent indy mechanic) replaced the SAIP in 2016 at 110k miles in the LX. Fortunately no known downstream damage.that I was aware of.
I (actually Toyota of SLO) replaced the SAIP in 2021 at 134k miles in my '06 4Runner. Again no downstream damage that I was aware of but that was less than 10K ago.

IH8SAIPs! And I love my '03 and '04 4Runners! Pre-VVTI so no SAIP.

 

[2001LC]

Replacing the S.A.I pump, is a temporary solution. The non replaceable .02 cent filter, will fail again. How long they last depends on environmental factors the most, IMHO.

When SAI pump or its main SW replaced. IM & TB gaskets are (should be) replaced, at that time also.

 

[henryone]

a few more pics
the pics side by side is how they were installed

View attachment 3003376

View attachment 3003377

View attachment 3003378

Just wanted to thank the OP on this diagnosis and post. I replaced the connnectors on my knock sensors after busting one off during a starter replacement several years ago when this was my DD. During connector change out I replaced the intake manifold gasket with a NAPA gasket set. After several months of running good, she started running rough and a got a host of codes indicating misfires at multiple cylinders. Did the carb cleaner spray diagnosis recommended here and saw the rpms rise.
New knock sensors and manifold gasket to proper torque, and all codes are gone and running like a champ.
Lesson learned; don’t over torque your mani gaskets.

View attachment 3152046

View attachment 3152047
ever get these from NAPA. The plastic is brittle. Use only genuine Toyota.

Just wanted to thank the OP on this diagnosis and post. I replaced the connnectors on my knock sensors after busting one off during a starter replacement several years ago when this was my DD. During connector change out I replaced the intake manifold gasket with a NAPA gasket set. After several months of running good, she started running rough and a got a host of codes indicating misfires at multiple cylinders. Did the carb cleaner spray diagnosis recommended here and saw the rpms rise.
New knock sensors and manifold gasket to proper torque, and all codes are gone and running like a champ.
Lesson learned; don’t over torque your mani gaskets.

View attachment 3152046

View attachment 3152047

View attachment 3152048

Same happened to me. Was getting lean codes and misfires and fuel trim was pegged. Couldn't find the leak. After a few days it got much worse and I could hear it hissing. Sprayed some brake cleaner to locate. Unbelievable. I'd just installed NAPA gaskets 7 months ago. Big mistake. The plastic is brittle. Please use only genuine Toyota parts.

 

[ToyotaTechnical]

Bump so this can save other cruiser owners as well. Pulled intake gaskets from a 260K mile vehicle. Only 20K miles on the aftermarket gaskets. Complete failure. Would have been disastrous if these pieces fell into the engine.

LTFT was at 17%. CEL of P0300. LTFT now at +/- 3%.

 

[2001LC]

Sorry, not trying to pick on anyone. So please, don't take personally.

Whereas, I only use Toyota gaskets, seals, O-rings & FIPGs. I'd be surprised, with an new aftermarket IM gasket just busting during or shortly thereafter. It's more likely, an install issue.

Those impression, "may" be a clue to install issue.

I cringe, when I see sand. I spend, a great deal of time clean top of engine, before & after R&R of intake manifolds. I power wash and blow with shop air, then vacuum before install. Most 4.7L with compromised compression. Is due to dust (sand) entering combustion camber. Either by lack of proper air filtration or sand dropped in during IM removal.
Sand remaining on top of gasket, is not a good sign to see.

Second; I take my time, placing in gasket, with white tabs up (98-05). Making sure, seated flush with head. They can get hung up on threads of studs.

Third; I gently place IM in place. They can and do get hung up going in. Work to drop in that last ~1 inch, all four corners at same time.
With the rubber gasket in the VVT (06-07). It's import never to even bump, the gasket on any hard surface. They split, if hit.

Fourth; I male sure all corners down, then start lightly snugging nuts of 4 corners, and then bolts using a crisscross pattern. So that pressure on gasket spreads evenly. I then torque down in crisscross & in stages ~4ft, 8ft then 13ftlbf.

Tip:
After cleaning, before pull IM. I bend outward (just a little), the engine hoist hooks. Since they are a point, IM gets hung up on.

 

[ToyotaTechnical]

Sorry, not trying to pick on anyone. So please, don't take personally.

This is not my work, so no offense taken. Just fixing others mess ups.

 

[Jack90210]

Do the new ('06-'07) intake manifold gaskets stay in place readily during re-assembly (when it's upside-down), or is there a trick to that?

 

[2001LC]

Do the new ('06-'07) intake manifold gaskets stay in place readily during re-assembly (when it's upside-down), or is there a trick to that?

The VVT rubber IM gaskets, hold themselves in very well.

Note: Be very careful not to bump gasket on hard surfaces, during IM install. Doing so, can cut the rubber gasket.

 

[chukstel]

Today I summoned up courage and take out my Intake manifold on 2000 year model as I have been having same issues with the OP and there are leaks all around the upper manifold and lower manifold gasket. I remove them apart and behold both gaskets are bad which I need to replace them.

My major concern now is when I opened the IM apart, there are pulls of oil inside the manifold. Is this normal and I should just clean up, replace the gaskets and reinstall back. But if abnormal, what should I look at to get the oil issue fixed?
Attached pics in triangle is where the oil is and the other side has no oil.
Secondly, manifold is dirty with oil too. Also the mechanic added silicone to the gaskets.

Genesis of my problem (3 yrs ago, I had radiator leak issue that caused overheating so I took it to a mechanic to fix the top gasket issue and since then I started having these misfire and fuel consumption issues. Took it back to him and he was unable to fix it up so I have been using it like that on very short drive.)

So for the long details and I am not taking over the tread from the OP. Just needs help to get it working normal again.