Valve cover and Oil pan bolt torque

there are only but a few leak points, on this water cooled engine.

1. valve cover gasket tops list.
2. the 2 distributor o-rings, leaks down bell housing.
3. or the distributor base housing not mounted and sealed by the book. (need book?)
4. front cam seal (cover off look)?
5. front crank seal (or the bolt was never set to 94ft/lbs, torque. 17mm head bolt.
6. pan never leaks its glued on day one in the Cami factory with RTV, unless prev. owner fiddled with it. (new oil pump done wrong)
7. last it the rear oil seal, rear to leak.

there are only 2 way sto find leaks, get it clean, drive short distance.
see what leaks.
or
use the dye kit, a kit with UV lamp and dye, pack.

id do a #! valve cover, the 60k mile inspection , adds one, and most of these cars get on 60k service, ever , so the gaskets are all hard.
and useless on every one ive ever seen.

see oll behind here>?
http://www.fixkick.com/t-belt/sneak-a-peek.html

main bearing cap bolts 36-39 ft. lbs. oil pan bolts 51-69 in. lbs. oil pan nuts 43-60 in. lbs. oil pan drain plug 33 ft. lbs. oil pump cover bolts 72-84 in. lbs. oil pump relief valve plug 29-36 ft. lbs. oil pump sprocket nut 25-28 ft. lbs. Rear oil seal retainer bolts 84-108 in. lbs. rocker arm shaft bolts 14-15 ft. lbs. rod bearing cap nuts 23-25 ft. lbs. silent shaft sprocket nut 22-28 ft. lbs. spark plugs 15-21 ft. lbs. thermostat housing-to-Engine bolts 86-114 in. lbs. timing belt tensioner bolt 32-40 ft. lbs. valve cover bolts 43-61 in. lbs.

Removal & Installation

2.4L Engine

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the engine oil.
3. Remove or disconnect the following:
   
   Negative battery cable Structural collar A/C compressor bracket to oil pan bolt Oil pan
   
4. Clean the oil pan and all gasket mating surfaces.

To install:

1. Install or connect the following:
   
   Oil pan gasket to the block after applying engine RTV at the oil pump parting line Oil pan. Torque the bolts to 105 inch lbs. (12 Nm). Structural collar Negative battery cable
   
2. Fill the crankcase to the correct level.
3. Start the engine, check for leaks and repair if necessary.

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the engine oil.
3. Remove or disconnect the following:
   
   Negative battery cable Structural collar A/C compressor bracket to oil pan bolt Oil pan
   
4. Clean the oil pan and all gasket mating surfaces.

To install:

1. Install or connect the following:
   
   Oil pan gasket to the block after applying engine RTV at the oil pump parting line Oil pan. Torque the bolts to 105 inch lbs. (12 Nm). Structural collar Negative battery cable
   
2. Fill the crankcase to the correct level.
3. Start the engine, check for leaks and repair if necessary.

3.0L Engine

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the engine oil.
3. Remove or disconnect the following:
   
   Negative battery cable Starter motor Front motor mount bracket Bending braces Torque converter dust shield Oil pan
   
   

   Fig. Oil pan mounting bolt tightening sequence-3.0L engine
   
   

To install:

1. Clean the oil pan all mating surfaces.
2. Apply RTV gasket material to the oil pan.
3. Install or connect the following:
   
   Oil pan. Tighten the bolts in sequence to 50 inch lbs. (6 Nm). Torque converter dust shield Bending braces Front motor mount bracket Starter motor Negative battery cable
   
4. Fill the crankcase to the correct level.
5. Start the engine, check for leaks and repair if necessary.

3.3L & 3.8L Engines

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the engine oil.
3. Remove or disconnect the following:
   
   Negative battery cable Engine oil dipstick Drive belt splash shield Strut to transaxle attaching bolt and loosen the strut to engine attaching bolts Transaxle case cover Oil pan fasteners Oil pan and gasket
   

To install:

1. Clean the oil pan and all mating surfaces.
2. Apply a 1 / 8 inch bead of gasket material at the parting line of the chain case cover and the real seal retainer.
3. Install or connect the following:
   
   New gasket on the oil pan Oil pan. Torque the bolts to 105 inch lbs. (12 Nm). Transaxle case cover All bending brace bolts Drive belt splash shield Engine oil dipstick Negative battery cable
   
4. Fill the crankcase to the correct level.
5. Start the engine, check for leaks and repair if necessary.

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the engine oil.
3. Remove or disconnect the following:
   
   Negative battery cable Engine oil dipstick Drive belt splash shield Strut to transaxle attaching bolt and loosen the strut to engine attaching bolts Transaxle case cover Oil pan fasteners Oil pan and gasket
   

To install:

1. Clean the oil pan and all mating surfaces.
2. Apply a 1 / 8 inch bead of gasket material at the parting line of the chain case cover and the real seal retainer.
3. Install or connect the following:
   
   New gasket on the oil pan Oil pan. Torque the bolts to 105 inch lbs. (12 Nm). Transaxle case cover All bending brace bolts Drive belt splash shield Engine oil dipstick Negative battery cable
   
4. Fill the crankcase to the correct level.
5. Start the engine, check for leaks and repair if necessary.

Three seals to check. easiest is the valve cover seal. Number and remove the 4 wires going into your spark plugs. remove 4 nuts holding the cover and replace seal.
Next easiest is the distributor O-ring. Remove air filter assembly remove the distributor cap, then the distributor. With the valve cover still off, loosen the 2 bolts that clamp the distributor down. Remove the 2 terminal leads going into the distributor (4 wire terminal/2 wire terminal) Mark the case of the distributor and the case of the head with one line so you can line it back up on reinstallation. remove the 3 bolts holding the distributor down. Replace O-ring. replace distributor, align, tighten the 2 bolts, then tighten the 3 bolts. replace terminal wiring and cap. replace air filter assembly. Replace valve cover with new gasket. Place spark plug wires back into their proper places. The last one is the oil pan gasket. Drain all oil and remove all blots holding the pan. drop the pan and replace the gasket. Put it all back into place. Do not over tighten the pan bolts as this will cause the gasket to deform, making it leak again.

4.8L, 5.3L and 6.0L Engines

1. • Timing mark alignment-4.8L, 5.3L & 6.0L
     
     
   • Locate the camshaft sprocket alignment mark in the 6 o'clock position and install the camshaft sprocket and timing chain
   • Camshaft sprocket bolts and tighten the camshaft sprocket bolts;
     1. Torque to: 26 ft. lbs. (35 Nm)
   • Oil pump
   NOTE: Do not lubricate the oil seal sealing surface.
   
2. Lubricate the outer edge of the oil seal with clean engine oil.
3. Lubricate the front cover oil seal bore with clean engine oil.
4. Install the crankshaft front oil seal with a suitable seal installer. NOTE: Do not apply any type sealant to the front cover gasket (unless specified). Special tools are used to properly align the engine front cover at the oil pan surface and to center the crankshaft front oil seal.
   
5. Install the front cover gasket, cover, and bolts onto the engine.
6. Install the front cover-to-oil pan bolts and do not overtighten.
7. Tighten the cover bolts finger tight and do not overtighten. J41480 installation-4.8L, 5.3L & 6.0L
   
   
8. Start the J41480 or other suitable tool to front cover bolts but don’t tighten the bolts yet. NOTE: Align the tapered legs of the tool with the machined alignment surfaces on the front cover.
   Seal alignment tool installation-4.8L, 5.3L & 6.0L
   
   
9. Install tool J41476 or other suitable tool.
10. Install the crankshaft balancer bolt and tighten the crankshaft balancer bolt by hand until snug but do not overtighten.
11. Tighten the J41480 bolts and front cover bolts;
    • Torque to: 18 ft. lbs. (25 Nm).
12. Remove the tools. NOTE: Place a straight edge across the engine block and front cover oil pan sealing surfaces. Avoid contact with the portion of the gasket that protrudes into the oil pan surface. Insert a feeler gauge between the front cover and the straight edge tool. The cover must be flush with the oil pan surface or no more than 0.5 mm (0.02 in) below flush. If the front cover-to-engine block oil pan surface alignment is not within specifications, repeat the cover alignment procedure. If the correct front cover-to-engine block alignment cannot be obtained, replace the front cover.
    
13. Snug the oil pan-to-cover bolts in order to position the cover at the pan rail.
14. Tighten the oil pan-to-front cover bolts;
    • Torque to: 18 ft. lbs. (25 Nm).
15. Tighten the front cover bolts;
    • Torque to: 18 ft. lbs. (25 Nm).
16. Install the crankshaft balancer and bolt (See: Crankshaft Damper).
17. Install the water pump (See: Water Pump).
18. Fill the engine to the proper level with oil.
19. Fill the engine to the proper level with coolant.
20. Test drive the vehicle to confirm the repairs.

6.6L Engine To Remove:
NOTE: The 6.6L engine uses gears in place of a timing chain. For removal and installation, please see the Camshaft and Lifters procedure. This procedure covers the removal of the front cover and seal.

1. Before servicing the vehicle refer to the precautions at the beginning of this section.
2. Remove the upper intake manifold sight shield as follows:
   • Remove the retaining bolt in the front of the shield
   • Lift up on the front of the shield, then lift the shield off the rear bracket
3. Drain the cooling system.
4. Remove or disconnect the following:
   • Negative battery cables
   • Right front wheel
   • Right front fender splash shield
   • Upper fan shroud
   • Fan clutch (See: Engine Fan and Clutch)
   • Drive belt
   • Oil dipstick tube
   • Thermostat housing crossover
   • Crankshaft damper (See: Crankshaft Damper)
   • Crankshaft front oil seal
   • Water pump (See: Water Pump)
   • Camshaft sensor electrical connector
   • Camshaft sensor bolt and sensor
   • Crankshaft Position (CKP) sensor connector, bolt and sensor
   • CKP sensor spacer bolts and spacer
   • 5 bolts securing the upper oil pan to the front cover
   • Bracket bolts and the bracket for the turbocharger outlet coolant pipe
   • Engine front cover bolts
   • Use a suitable seal cutter to separate the front cover from the cylinder block and upper oil pan NOTE: Do not bend the turbocharger outlet pipe.
     
   • O-ring from the front cover Engine front cover-6.6L engine
     
     
   • Oil pressure relief valve from the front cover

To Install:

1. Clean and inspect all sealing surfaces.
2. Install or connect the following:
   • Oil pressure relief valve with a new O-ring and tighten the valve
     1. Torque to: 30 ft. lbs. (41 Nm)
3. Apply a 1/8 in. (2-3mm) wide to 1/16 in. (0.5-1.5mm) high bead of sealant to the front cover sealing surfaces to the engine block and oil pan.
4. Install or connect the following:
   • New front cover O-ring after lubricating it with engine oil
   • Front cover and bolts and tighten the front cover bolts
     1. Torque to: 15 ft. lbs. (20 Nm)
   • Upper oil pan-to-front cover bolts and tighten the bolts
     1. Torque to: 15 ft. lbs. (20 Nm)
   • Turbocharger coolant outlet pipe bracket and bolts and tighten the bolts
     1. Torque to: 15 ft. lbs. (20 Nm).
   • Camshaft sensor and bolt and tighten the bolt
     1. Torque to: 80 inch lbs. (9 Nm)
   • Camshaft sensor connector NOTE: The CKP sensor spacers are machined with different timing positions. If you have to replace a spacer, make sure it has the same part number.
     
   • CKP sensor spacer and spacer bolts and tighten the bolts
     1. Torque to: 89 inch lbs. (10 Nm)
   • CKP sensor and bolt and tighten the bolt
     1. Torque to: 89 inch lbs. (10 Nm)
   • Water pump (See: Water Pump)
   • Crankshaft front oil seal
   • Crankshaft damper (See: Crankshaft Damper)
   • Thermostat housing crossover
   • Oil fill tube
   • Drive belt
   • Upper fan shroud
   • Right front fender splash shield and wheel
   • Negative battery cables
5. Refill the cooling system with the proper type and quantity of antifreeze.
6. Inspect the engine for leaks.
7. Test drive the vehicle to confirm the repairs.

Im assuming you mean the oil pan gasket? Oil pan gaskets are very time consuming to change on most vehicles, expecially front wheel drive because of the space. First crawl under and locate the oil pan (don't confuse with the bottom of the transmission lol). On my front wheel drive vehicle, I had to disconnect the AC lines to get to it (what a headache that was). Getting access to the oil pan is the hardest part but once you have access, the process is realitively easy. Drain the oil first or you will be taking a bath. remove the screws, clean the area the gasket is going to be touching, replace gasket and re torque the bolts to mfg. specs in sequential order as to not bind or pinch the gasket. Also, is it leaking from the valve cover? Valve cover gaskets are much easier to replace than oil pan gaskets.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/matthew_d24b835e574ef6ca

not oil pan but gasket remove oil pan scrape off all old gasket and put on new one the best thin to do is glue it on the oil pan first and let dry with bolt holes in line the glue it to block but this might no be the problem headgasket could leak oil pump gasket valve cover gasket

The toyota previa uses a formed silicone gasket for the valve cover and the cover is held in place by metric shoulder bolts ( 10mm). The valve gasket leaks because you can't get enough preload on the bolts to re-seat the old gasket when it gets old and shrinks. The shoulder bolts only allow you to tighten the gasket enough to seat the shoulder on the bolt. If you continue to torque down the suspected bolts, you will snap the bolt off ( don't ask me how I know this ). You can either 1.)replace the old gasket with a new one or 2.) remove the existing bolts around the leak area and put in new metric bolts that do not have a shoulder. You may want to put in a small sleeve into the existing bolt hole but shorter than the thickness of the valve cover to account for the smaller diameter bolt. You can now torque down the bolt and get enough preload to seal the valve cover without removing the old gasket. Make sure you use a torque wrench ( in-lbs) or be very careful not to snap these small valve cover bolts.

then you need to replace the gaskets drain oil from oil pan take all bolts out and drop the pan as far as valve pan covers buy rubber gaskets not cork they are a lot more pliable and less prone to leak

Jack the vehicle up so you have enough room to work on the truck.
Then use an oil catcher pan,,and let the oil plug go,,drain out all of the oil,,,then remove all of the oil pan mounting bolts, leaving one on each side MIDDLE,, so the pan doesnt fall on your head.
Then carefullt remove the last two bolts while supporting the pan.
When you have the pan down, and out of the way,,you shoul dbe able to see the two oil pump mounting bolts up near the crank shaft above the pickup tube.
Remove the two bolts,,then carefully take down the oil pump.
Be sure to install the new pump and gasket correctly, and ,make sure the oil pump drive shaft (which also drives the distributor) is connecting properly.
Then re-install the oil pan,,,with a new gasket,,make sure the gasket does not slip away from the seams,,and only torque the oil pan bolts to around 14lbs per sqaure inch,,,better still check your manual to find proper torque specs.
Now,,you can fill with fresh oil,take it down off the jack stands,,and start the vehicle,(you can pull the valve cover off,,or if you can see the lifters),,make sure the oil is getting to the top end of the motor.
and then Congratulations,,you are done!!