New to me 2000 OBS 3500
 

Hi everyone,

This is my first post here. I just got home looking at a 2000 Chevy 3500 Crew cab long bed truck. Decided on purchasing it. Actually as I'm typing this it is on the way home on a trailer. It's a single rear wheel with the Vortec 350. 217k miles. I had no idea they made OBS trucks in 2000. Anyways it has a really bad water leak. It just pours. It looks to be coming from the left side of the engine (looking from front) dripping onto the front axle. Is there a freeze plug there? What trouble could I be getting myself into?

Thanks for adding me to this forum,
Isaac

Deep, deep trouble. :D Welcome to the forum.

There’s several possibilities for the leak, but if it’s as bad as you describe, you shouldn’t have too much difficulty finding it with a good visual inspection.

Is it leaking all the time or just when the engine is running?

For better visibility, remove the air cleaner and/or the tire so you can inspect through the wheel well.

Hi,

Sorry I have been out of town for a while. Just started working on it today, removed both front wheelwells and a small skid plate underneath. Now I'm wondering if it may be leaking on the right side looking from the front. I couldn't see too well but it looks like it leaks from up near the engine mount and drips on the front axle. It leaks all the time by the way. I'll look some more tomorrow hopefully. Did find out it has a new/rebuilt transmission :D Found a jasper sticker.

Thanks

If you’re not seeing any coolant above the mount, chances are good it’s the block drain plug or a freeze plug.

Use a mirror and flashlight to inspect the block under the exhaust manifold.

It's a freeze plug! Front on driver bank. How should I go about replacing this? Looks like engine mount may be in the way, not sure what else.

1) Be prepared for a mess. Even if you drain the coolant there will still be quite a bit that comes out when the plug is removed. Have a catch pan/bucket and floor dry (or equivalent) at the ready and wear eye/face protection.

2) Decide how you want it repaired.

The “proper” repair is to install a new steel plug, but they require a hammer and driver tool, as well as accessibility to install properly. This could mean removing the mount or differential.

A second option is to use expandable rubber plugs (aka marine or pipe plugs) that slip into place and seal the hole using a nut and screw to swell the rubber. These are much easier to install if using a hammer and driver is impractical.

Either type of plug is available at any parts store - some hardware stores carry a limited selection of both as well.

You’ll need 1-1/2” or 1-5/8” - I can’t remember which, but they’re reasonably cheap so it’s worth it to get both and save yourself an unnecessary trip.

A 3rd option is to get a block heater kit that’s intended for installation in place of the freeze plug. These aren’t a necessity for gas engines, but if you live in an area that sees temps below zero, and you won’t be parking the truck in a garage or shed, it would add an extra layer of protection, as well as ease cold starting.

3) Regardless of which option you choose, the old plug can be removed with a hammer and punch. Place the punch against the edge of the plug and hit it firmly until the plug breaks loose. If it doesn’t fall out of the block, it can be removed with a pair of pliers.

4) Use emery cloth (or equivalent) to clean the edges of the block bore. If the corrosion is particularly difficult to remove, spray with penetrating oil and switch to steel wool or a scotch brite pad. If it’s really bad, a reamer or wire brush will also work, but I don’t recommend them unless it’s necessary.

The bore is properly cleaned when you can see clean metal all the way around. Follow up with brake or carb cleaner on a rag to remove residue from the bore.

5) If installing a steel plug, apply a thin layer of RTV silicone or liquid gasket to the perimeter of the new plug. Use a hammer and driver tool (sockets often work well) to install the plug flush with the exterior of the block wall. Note that some plugs have a rolled lip on them - if that’s present, drive the plug in until the lip seats.

If installing a rubber plug, make sure the block and plug are free of residue and debris. The plugs are usually marked/stamped with the correct torque, but generally, 10-15 ft-lbs is all it needs.

If installing a block heater, follow the instructions included with the heater.

6) It will help bleed the cooling system if you leave the radiator cap off and allow the engine to idle up to temperature the first time. Once the thermostat opens, run the heater at full heat/full blower speed for 5 minutes to bleed the heater core.

Thanks so much for the info. I think I will try to tackle it tomorrow if I can. And I'll eventually figure it out, but do you know how to remove the motor mount (Or atleast the bracket that is held in by the three bolts on block)? Haven't been able to find a youtube video where the engine was not removed to replace it.

Thanks!

1) Position a jack on the tab at the rear of the block (see illustration). A bottle or screw type jack will be easiest to work with but may require blocks to make up the height.

2) Raise the engine slightly - just enough to relieve tension from the mount through bolt so it can be removed.

3) Once the through bolt is removed, raise the engine far enough to access the mount bolts on the block for removal.

https://cimg1.ibsrv.net/gimg/chevrol...4a95fcbb3.jpeg
Arrow marks correct position.

OK I removed the center bolt this morning. Jacked up the engine with a bottle jack and a 2x4 on the oilpan Because I couldn't find a way to get to that tab. Now I can't remove the three mounting bolts! They're at an angle and it's hard for me to see them or get a good grip on them. Especially the one at the bottom. Do you think some ratcheting wrenches with a swivel thing on it would work? Or should I try to figure out how to jack up the tab?

Thanks
https://cimg4.ibsrv.net/gimg/chevrol...ff0d8648d7.jpg
https://cimg3.ibsrv.net/gimg/chevrol...09621cc2dd.jpg

I don’t think swivel wrenches would help, but you can try.

There should be quite a bit of room to lift the engine up farther for better access, but I’d recommend relocating the jack. If you can’t access the tab, try the edge of the oil pan where it meets the block or on the left side of the trans-to-engine mating surface.

It will also help the engine lift if you loosen the through bolt on the other mount.