CELICA GT (2000)




Intake Manifold Gasket Replacement



The Celica GT's 1ZZ-FE engine had a problem that is outlined in the Toyota Technical Service Bulletin below. When the temperature drops below 0C an induction manifold leak would cause the engine to run lean and the check engine light/malfunction indicator lamp (MIL) will come on as the On Board Diagnostics detects one or more fault conditions.


Toyota TSB EG046-07Toyota TSB EG046-07  M.I.L. "ON" DTC P0171, P030#, And / Or P0133 Engine Running Lean In Subfreezing Ambient Temperatures.


Symptoms can include loss of power at low revs (below 2000/2500rpm), uneven idle, hesitance / poor throttle response from idle,(to the point where you can stall).



Tools used




Check Engine Light / M.I.L. On
Check Emgine Light On

P0300 and P0302 PID Codes from ODBII
P0300 and P0302 PID Codes from ODBII

The above shows the check engine light and the associated OBDII PID codes, P0300:Random/Multiple Cylinder Misfire Detected, P0302:Cylinder 2 Misfire Detected Before undertaking the gasket replacement I swapped cylinder 2 and 3's ignition coils, the code P0302 was still generated when the fault occurred! P0302 Update
   You can read the codes and reset the Check Engine light with a cheap OBDII scanner such as the GS/MS-300 shown to the left, and look-up the meaning of Pxxxx PIDs using my OBD Look-up page!

 You can also buy Bluetooth OBDII dongles on eBay from around $36, which you can use in conjunction with a laptop or PDA, to read PID codes,capture data, and reset your check engine light. These are the cheapest solutions, OBDII scanners can cost $100s for units which capture live data, do logging etc.
You will need an OBDII scanner to reset you check engine light / MIL!


Below is the replacement Induction Manifold Gasket; I used a Fel-Pro Gasket, PN:MS93942, as they have a good reputation and Advance Auto Parts had a free shipping offer. This made the cost less than $6, which was more attractive than a long drive to the nearest dealer. However, the OEM part,(17171-22060) would never be a bad option!

Fel-Pro MS93942 Intake Manifold Gasket
MS93942

The Toyota TSB explains in detail how to replace the intake manifold gasket, it states the throttle body should be removed, entailing the draining of the cooling system and its refill and bleeding. This would be a major pain, and the job can be accomplished by detaching the throttle body from the intake manifold and leaving supported by its hoses; as outlined below.

Firstly, unclip the sensor from the air box, unplug its electrical connector and move it out of the way. Then use a 10mm socket to remove the air intake tube. A 12mm socket,not too shallow; can be used to detach the throttle body from the intake manifold. Now the cosmetic plastic cover from the engine can be removed with a 10mm socket and pliers for the plastic plugs. The cosmetic cover for the coolant etc, can be removed with a small Torx driver,(T20) or dexterous fingernails,(to just pull the center out).

Move hoses so the air intake tube can be removed
Move hoses so the intake tube can be removed

Engine bay with intake tube removed
Air intake tube removed

The Throttle Body detached from the intake manifold
Detach the throttle body

Undo the 2 Nuts 12mm and 3 bolts 12mm on top
Undo the 2 Nuts 12mm and 3 bolts 12mm on top

Undo the lower 12mm bolt
Undo the lower 12mm bolt

Remove the hoses from the manifold, The one below is held on with a big clip!
Remove the various hoses from the manifold

The manifold can be gently twisted out
The manifold can be gently twisted out


The above pictures illustrate the removal of the induction manifold. I used a 6 inch extension bar and a 12mm socket on the top nuts and bolts. I then used a torque wrench, because of its longer handle, and a swivel joint,(a short extension may also work), to undo the bottom bolt. Two of the hoses are easy to access and remove,one having a wire retaining clips the other just pulls off. The third ,illustrated, has a bigger clip. It needed a small pair of locking pliers,(mine cost a couple of dollars at Walmart); to hold open the retaining clip, the hose was then detached by gently pulling the manifold away from it. I left the pliers in place!! The whole manifold could then be gently twisted out, as shown.

The engine block before and after cleaning
The engine block before and after cleaning

Old gasket, no gasket, new gasket
Old gasket, no gasket, new gasket

New gasket in place!
New gasket in place!

Throttle body gasket sealed
Throttle body gasket sealed


The final pictures, show the removal of the old gasket, the engine block and manifold before and after cleaning. I used both isopropyl alcohol and carb. cleaner to remove the oil and grime. Once the gasket was fitted the manifold was re-installed, for this I used a torque wrench and progressively tightened the nuts and bolts, to the specified Torque,(30 N.m (306 kgf.cm, 22 ft.lbf)). The only difficulty was re-fitting that hose! This was achieved by lining it up, and then pushing it from behind with a medium flat blade screwdriver, then releasing the locking pliers. I applied some 'liquid gasket',(Permatex Ultra_copper) to the throttle body gasket, as the manual states it should be replaced every time; then tightened it up to the Torque specified in the shop manual ,(21 N.m (210 kgf.cm, 15 ft.lbf). After re-assemble, I gave the engine bay a final inspection, started the car and used my GS-300 to clear the check engine light / MIL. The car drove noticeably better after driving for several minutes!

Unfortunately P0302 came back... The one cold frosty winter's morning, shortly after pulling off from the driveway, the car faltered, I hit the gas and .. Boom! Huge cloud of soke from the back of the car! The P0302 was caused by a sticking piston ring! Which broke and cost me an engine!

It could be a good idea to remove the Negative battery cable before work 1. for extra safety 2. To Reset the ECU,(Engine Control Unit) adaptive memory; otherwise it starts out with its values from the fault gasket, and takes a fem minutes driving to re-learn . :o)


Disclaimer:

This page is ONLY to show what I did to my Celica!
I take NO responsibility for anything arising from information given here nor do I guarantee its correctness!