Interference VG30i Noob BENT VALVES

jesseagreen · Feb 5th, 2008, 09:11 PM

Hey guys,

First post on the Forums. Needing help.

Ride: 1988 Pathfinder 4x4 V6 SE VG30i
Problem: timing belt snapped on freeway bent all 12 valves
Purchased: manufacturers heads for 300bucks with valve job (cheaper than valve job qoute), Gasket Kit, Timing Belt, Timing belt tensioner.

Question below here some pics...

Here is how my Engine bay looks like right now hehe

All 12 valves are bent. here is a pic of one head

Here is a close up showing gaps on intake and exhaust valves

THE NEW HEADS

SO now my questions... Now that im putting this bitch back together I need to set the Cams and Crank in the correct Position.

1st - How to i determinant Top Dead Center. I Know i need to Make sure the #1 Cylinder needs to be up the peak but doesn't it do that at each 180 Degree of the crank? or once every 360? I havent played with it much.

2nd Once i have the Crank/Piston Set to TDC Do i just line up the cam Markings to thier respected position then install the rockers that push the valves to their respected cylinders?

Sorry im new to Interference engines and just dont want to mess up more valves since this has been a pain in the but with all the crap i needed to remove to get to this point.

Also Gaskets question. DO i need some type of sealent for the heads/exhaust/intake gaskets? or just slap the new ones on after i clean the respected surfaces?. if so any recommendations?

jesseagreen · Feb 5th, 2008, 09:17 PM

OH another quesition. The book ive been using as reference advised me saving the headbolts and keeping them in the same order as i took them out for reuse?. Is this right? should i get new ones? I made sure to mark each one in a cardboard box to put them back but just wanted to ask. Also anyone know the tourqe off hand?

californiak · Feb 20th, 2008, 04:34 PM

Did you finish this job yet? If not I can email you pix from Haynes repair manual and give you the tork specs. I may have the same job on my hand soon, I think my timing belt failed also, not sure yet. Where did you get the heads and did you also have any pistons damaged? BTW any good library in your area should have the car repair manuals for you to borrow.

californiak · Feb 20th, 2008, 04:37 PM

Oh, your pics do not show on net, can you email them to me so I know what to expect when I get into my engine: morho1@earthlink.net

jesseagreen · Feb 20th, 2008, 05:01 PM

Quote:

Originally Posted by californiak

Oh, your pics do not show on net, can you email them to me so I know what to expect when I get into my engine: morho1@earthlink.net

Hum. I dont know why the pics didnt show up. I Have her all fixed now. about 600 miles on the new heads with little problems. SO heres my short story. They were going to charge me about 450 in just labor for the valve job. ALl 12 were bent and would need new giulds so i just called around junk yards and More importantly Engine resellers. They normly will have cheaper rebiult heads as long has yours are ok. AKA not cracked warped and stuff.

WHen you get the new ones make sure you get new EXHAUST STUDS. The uses ones tend to break well before correct tourqe. I lost 2 of them on installation and now have a small exhaust leak.

Next When reinstalling make sure you line up the studs on the exaust then sit on top of the block. the manifolds are hard to move if you do it otherwise. Before you blot the head on also install the intake manifold. its a lot easier when everything is kinda free moving.

Overall it was a fun project. I would love to answer any questions. my email is jesseagreen@gmail.com. Email me if ya want my number. I will post the pics in a bit.

This took me one hard weekend removing crap... and one weekend for install.

Oh. Timing belt is easy once you know how to do it. The lines on the new belt line up with the crank dots and the cams. so its hard to mess up. Don't loose the crank key. if you do its no biggy just another stop at autozone.

OH for test start after everything is bolted back on.. Make sure your A/B vavlve is installed or your car wont idle.. I was scared i messed up on something then releized not having that A/B Vavel creates a huge intake leak

californiak · Feb 20th, 2008, 06:18 PM

Thanks for the offer, I may just take u up on that. Now the pix are showing. I don't know if I tackle this job or just junk the car. I am not even sure if it is the belt that failed, so far all I know is that the distributor is not turning when I crank up the engine so I suspect that what it is - didn't have time to look any more into it.

jesseagreen · Feb 20th, 2008, 07:18 PM

jesseagreen/PathfinderTopEndrebiuld - Photobucket - Video and Image Hosting
PICS

Things i needed to buy.

ALot of hoses just becuase the old ones were crap.
Thermostat since you get an opportunity to get to the housing might as well get it done
REmanfacture heads
Gaskets top end (found on ebay for 50ish)
New clamps for houses just cuz the factory ones sucks

Rented from autozone
Torque wrench 90 dollar deposit.. get it all back
crank Puller (used the biggest 3 hook one and a washer to remove)

New spark plugs since i was there.
New distributor and cap (Other one looked like crap)
Moly grease for the rubber piece where the cam exits the head.

jesseagreen · Feb 20th, 2008, 07:22 PM

Quote:

Originally Posted by californiak

Thanks for the offer, I may just take u up on that. Now the pix are showing. I don't know if I tackle this job or just junk the car. I am not even sure if it is the belt that failed, so far all I know is that the distributor is not turning when I crank up the engine so I suspect that what it is - didn't have time to look any more into it.

Yeah it wasnt an easy job and its gets pretty stressfull. What symptoms did you have that makes you feel that you lost the timing belt?

I was driving down the Highway at about 70, went to accelerate to pass a car in the lane i needed, It felt like the pathy didnt want to go so i stept on the gass more and then I heard a loud pop and car just died and wouldn't start after that.. I could hear the crank turn but thats it

californiak · Feb 20th, 2008, 07:39 PM

Same thing, cruizing on fwy at 60 mph (LA traffic - that's as fast as you can go. Ha Ha Ha) and it just died, had it towed home, so far I did not take a look at the timing belt, just looking around I noticed the distributor is not rotating and I figured its engaged in driver side cam so the cam must not be turning when I crank the engine. Tomorrow I will take all the crap from the front of the engine and see if it is the timing belt, the thing is I have the timing belt and water pump in the back of the car and was just waiting for better weather to do it. Bummer!!!!

I am only hoping the pistons are OK otherwise why bother with taking the heads of. I gues you got lucky and your pistons were fine. Sometimes you get nice big hole on top of one or two - I read this somewhere on the board. Oh, well.

californiak · Feb 20th, 2008, 08:06 PM

One last thing. How much did you spent total to fix it, approx?

jesseagreen · Feb 20th, 2008, 08:57 PM

Ill tell you right now i know your timing belt is gone. Your correct in concluding that if the crank spins the cap/rotter should spin.. Not spinning at all means the belt is broke or Warn down to nothing and resting on the crank teeth with nothing to grab.

at that speeds you are looking at bent vavles for sure. dispite any false hope you might read on fourms

I would say its worth it if your willing to spend 2 weekends and have good tools and a good book as a giude.

IN regards for the pistion damange... I have also heard about people cracking pistions... After looking at the vavles vs the pistons i find it hard to belive that you can really really mess pistions if its a quick break on the belt. I barly had any scoreing on the pistions as shown at the pics and thats after me hitting the gas at 70 miles an hour. Maybe if this was a high proformance engine pushing 300+HP but i would say it doesnt cost anything but time and work to rip your car appart to inspect to deside on taking on the project.

Cost can change depending on parts availblity.

Vavle job cost depends on how many vavles are bent.. I was looking at 450 labor with all 12 bent (I think you will have all 12 bent to

See if you can find some used heads or remanufacture ones from a engene resller. (its a common engine so you should get a couple offers (hopefully)

so if you can find heads for under 500 i think its worth it if the other parts of the truck are good and worth the fix.

Other than that

Timing belt 30
Timing belt tentioner 30
thermostat (optional)
water pump (optional)
Heads or vavle job 300-700???
Gasket kit 60
Molly grease 5
Cap&Roter (if worn) 25
MIsc hose replacment,clamps& random crap 25
Oil 15
Oil filter 10
----------------------------------------------------

So for me 4 days work.. 500ish Beats paying someone to do this job... believe me at 60 bucks an hour... haha.. yeah..

I also had to Rent a torque wrench and pully puller

Its worth it if you can get a good deal on the head and have all the tools.