Mysterious oil leak.

[eddiekimberly]

I am in the process of doing new oil lines and new connectors to the oil filter housing. While under my truck I noticed a bit of oil coming from the front of the 350 engine. I think I may be looking at a new oil pan gasket, timing chain gasket and front main seal. How big a pain in the ass is this gonna be? What parts do I need and which ones should I avoid? TIA.

[1997SierraSLT]

most likely timing chain cover gasket/crankshaft lip seal is weaping.

 

you'll need to drain antifreeze, remove serpentine belt, fan clutch, water pump, crankshaft pulley, and harmonic balancer. The harmonic balance will require a special puller to remove it.

[ifixedit]

Just finished this exact same job on a 77- 350, all is pretty much the same as what you got now but a bit different accessory drive set up, sure wish mine was serpentine too! It's not that big of a job, just be patient and take your time.

 

I found the front seal (the one around the harmonic balancer) on the timing chain cover to be the one leaking the worst, the seal was as stiff as a cob and was basically doing zero other than taking up space. To do things properly you also have to drop or at least lower the oil pan. Here's what I'd do: While you have it apart, order yourself a two-piece timing cover set, this eliminates the future hassle of having to drop the oil pan should you ever decide to tear into the engine / camshaft / timing chain area in the future. You can get them at Summit Racing cheap. Paying close attention to the area where the new lower cover seal meets the bottom of the block and the oil pan is crucial, this is a leak prone area, be sure it will well sealed with a little extra RTV behind the gasket.

 

While you're in there you may want to take a look at the timing chain and gears, especially if it has the nylon lower gear, get rid of that junk if it does. Easy to do while you've got it opened up. If you don't have a puller, most auto parts places will have one for you, they're not expensive and will also work to pull the lower timing chain gear. I've got one of these >> http://www.princessauto.com/en/detail/lisle-harmonic-balancer-puller/A-p2918050e

[1997SierraSLT]

the Vortec has a plastic timing chain cover and it's a bit different in design than the vintage 350ci engines. I don't believe you'll need to drop the front portion of the oil pan.

[eddiekimberly]

Appreciate the replies. THIS will be a fun project for my wife and I. Yes, I have a wife that doesn't mind a little grease. I will get to it if it ever stops raining so I can do the dang oil filter housing gasket.

[eddiekimberly]

What particular brands of gaskets do you guys find to work better. Have used tons of fel-pro and Victor Reinz with about the same luck. But I know some rides prefer one over the other. Which one do our trucks prefer?

[eddiekimberly]

Part Price Quantity Total Remove

1996 CHEVROLET K1500 PICKUP 5.7L V8

Click to Jump to This Part Listing in the Part CatalogEngine : Oil Pan Gasket

FEL-PRO Part # OS34500R {#14088505} PermaDry®

Flag indicates this part fits vehicles sold in the US Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Flag indicates this part fits vehicles sold in the Canadian Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. PermaDry® molded rubber Gasket. incl.

Do you also need a new Oil Filter?

A $17.91 $17.91 Remove Part

Click to Jump to This Part Listing in the Part CatalogEngine : Crankshaft Seal

FEL-PRO Part # BS40656 {#BS40515, JV1620, JV1656} Rear Main Seal Set

Flag indicates this part fits vehicles sold in the US Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Flag indicates this part fits vehicles sold in the Canadian Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Rear; PTFE Rubber; One-piece; Improved design; Rear Main Seal Set

A $16.15 $16.15 Remove Part

Click to Jump to This Part Listing in the Part CatalogEngine : Timing Set

SEALED POWER Part # KT3499SA5

Flag indicates this part fits vehicles sold in the US Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Flag indicates this part fits vehicles sold in the Canadian Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Timing Set - 3 Pc.; Incl. hardened cam sprocket; w/.405" tooth width sprocket; (1) 222-499; (1) 223-732T; (1) 223-797

B $43.79 $43.79 Remove Part

Click to Jump to This Part Listing in the Part CatalogEngine : Timing Cover Gasket Set

VICTOR REINZ Part # JV5111 Material: Victo-Tech

Flag indicates this part fits vehicles sold in the US Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Flag indicates this part fits vehicles sold in the Canadian Market. It does not indicate where the part was made -- manufacturers produce parts in multiple factories worldwide. Oil Pump Gasket Included: No; Repair Sleeve Included: No; Sealant Included: No; Timing Cover Gasket Material: Victo-Tech; 1st Design; 58mm O.D. Seal

A

 

If you can understand THIS, it is the shopping list as a stands right now.

[1997SierraSLT]

you can buy a timing cover kit from Advance Auto parts. It has the timing cover with crankshaft lip seal already installed, timing cover gasket, gaskets for the water pump, and o-ring for the crankshaft position sensor. That's really all you need for about $30 total.

 

Advance Auto Parts also sells the external oil cooler supply/return hoses going from the oil filter housing up to the external cooler within the radiator. The hoses are only about $30 each.

 

Unless you've got extremely high mileage or there is a lot of slop, I would not consider changing the timing chain set.

[eddiekimberly]

Well that's not bad. I'll look at it. Thanks