Floating Doc
Floating Doc GRM+ Memberand SuperDork
8/10/19 9:54 a.m.

My mega mileage TBI 350 88 Silverado continues to run perfectly, but it is not without issues. It probably needs intake manifold gaskets or head gaskets, since it goes through more coolant than oil.

The valve guides need replacing, I get a little smoke when it first starts up. The odometer doesn't work, but adding oil is a rare event.

It'll run down the highway all day at 70, unloaded, or pulling a U-Haul car hauler with a Miata. I've taken it on a few road trips of up to 1800 miles.

When I got the truck the drain plug in the oil pan had been helicoiled. After a few years, it started to seep, and eventually failed. I bought a Time-Sert kit and that held up for several years. Unfortunately the Time-Sert insert backed out a couple of days ago and the retapped threads in the sheet metal pan are stripped.

I've looked at a couple of options for keeping the same pan on the truck at least temporarily. I've ordered a rubber compression type plug made by dorman, that looks like a toggle bolt. I'm pretty reluctant to put this thing into my oil pan because if it fails or I decide not to try another solution, I've got the toggle portion still in there.

After taking a better look at the photo, I see that it's not threaded all of the way to the end of the rod, so losing the toggle in the pan seems unlikely. However, getting it out once you put it in is probably impossible.

I also ordered something called an Eco-plug which appears to just be a rubber plug with some really strong rare Earth magnet in it. It's gotten some really good reviews, but who knows?

So, now I've got some decisions to make, and I could use some opinions from the hive.

Anyone care to comment on the temporary solutions?

How difficult will the oil pan replacement be? As noted in the title, this is not a 4x4. I've never done just an oil pan, do you have to replace front or rear main seals?

Does it make sense to even bother repairing it, when eventually it's going to need an engine? It's so high mileage, I was advised not to even do the valve guides. It still holds about 15 to 20 lb of oil pressure when hot, and idling in gear, and as mentioned runs like a low mileage engine. I haven't had any problems with plug fouling either.

A remanufactured engine runs around 1300, a brand new GM one is about 2000. Although I'm marginally capable and have most of the tools, minus a hoist, I'm unlikely to swap it myself. 

I'm not sure I would put that into this truck, even though it's rust free. I'd rather have something newer and with more crash protection, but money is a real issue right now.


Pete Gossett
Pete Gossett GRM+ Memberand MegaDork
8/10/19 10:07 a.m.

In reply to Floating Doc :

I’ve never heard of that eco plug, but if the reviews are good that’s likely what I’d try for a temporary fix. 

Alternately, are you interested in trading your truck for an 06 P71?

snailmont5oh Dork
8/10/19 10:07 a.m.

Time-sert+JBWeld permanent thread sealant? 

wae SuperDork
8/10/19 10:09 a.m.

I don't know how tough or easy the oil pan swap would be, but unless you need to pull the crank pulley or the transmission you're not going to disturb the front or rear main seal.  Oil pans are usually a matter of getting the stuff that's between the pan and the ground out of the way and then they drop off, a new gasket goes on, and the replacement bolts up.  No big deal unless you have a subframe or something that is in the way.

That toggle bolt thing looks fairly brilliant, though!  I'd just go that route first to see if it seals up.  If it does come apart, the worst case is you have the inside toggle part rolling around in there but it's not going to hurt anything.  I suppose if you wanted to be really pedantic about it you could determine how much oil it displaces and subtract that amount from the oil added during an oil change to keep from overfilling by, what, a third of an ounce? cheeky

If you're not in love with the truck, then I'd do a temp seal on the pan until you're ready to sell it and just be done.  You won't get as much with a tired old engine as you would with a fresh one, but you're not likely to get $2,000+labor more for the truck with a fresh motor v/s as-is.  On the other hand, swapping the motor wouldn't be a huge task, so swapping the motor with either the crate or the reman would breathe more life into the truck than spending the same amount of money on a different truck - especially if you did it yourself over a couple weekends or something.

Curtis GRM+ Memberand UltimaDork
8/10/19 10:18 a.m.

Low-mileage TBI engines are $500 with a warranty from many junkyards.  Could be a nice way to refresh things without too much money.

Oil pan swaps aren't the end of the world.  Pull the bolts out of the motor mounts and lift the engine 4".  While you're at it, pull the timing cover and do a chain while you're in there.  It's another hour of work but it saves you pulling all that stuff later when the chain gets slop in it.

Curtis GRM+ Memberand UltimaDork
8/10/19 10:20 a.m.

That toggle should work fine if you have the right surface area on the oustide of the pan.  Don't worry about losing the toggle.  You never have to take the rubber part off the whole way.  Just loosen it to drain but don't take it off.  If you do go too far and the plug comes off, a telescopic magnet will get it back.

The design on that one looks like you can't mess it up.  Looks like they assemble it and then smoosh the threads so it can't come apart.  The only downside is that you may never get it out if it doesn't seal (at least not without taking the pan off).  I suppose you could cut the bolt and leave the toggle end in the sump.  It's not like it's small enough to plug up anything.

Floating Doc
Floating Doc GRM+ Memberand SuperDork
8/10/19 11:47 a.m.
Pete Gossett said:

In reply to Floating Doc :

I’ve never heard of that eco plug, but if the reviews are good that’s likely what I’d try for a temporary fix. 

Alternately, are you interested in trading your truck for an 06 P71?

I've had three panther body crown vics. The last was a 95 p71. I'd love to have another, but there's no way to fit it into my fleet. 

Currently have a Mazda 5 van for my wife, my 04 Ralliart wagon for my daily, a miata for my autocross car, and the truck for a backup driver / truck stuff. I'm planning to pick up a trailer for towing the Miata to events.

wvumtnbkr GRM+ Memberand UberDork
8/10/19 11:51 a.m.

Weld a nut on the outside of the pan to the hole?


I replaced the con rod bearings in a g body without removing the engine.


If you need to replace the oil pan, just lift it off the mounts like Curtis said.

bearmtnmartin GRM+ Memberand SuperDork
8/10/19 11:54 a.m.
No Time
No Time Dork
8/10/19 1:09 p.m.
snailmont5oh said:

Time-sert+JBWeld permanent thread sealant? 

Maybe add a Fumoto valve to eliminate wear in the thread repair. 

pirate HalfDork
8/10/19 2:06 p.m.

Similar to the Fumoto valve. If you can retap or drill to a new size then add the following you never have to unscrew the oil pan plug. These come in a variety of sizes.

Quick Drain Oil Pan Coupler, 22mm x 1.5 Male

Click for a larger picture of Quick Drain Oil Pan Coupler, 22mm x 1.5 Male

Put a dry disconnect on your drain plug for cleaner oil changes! The Quick-Drain Pan Coupler replaces your oil drain plug with a self-sealing quick-connect coupler. 

Oil stays in the pan until you connect the Quick-Drain Female Coupler (Part No. 3228-350), sold separately. The female coupler accepts a 5/8" ID hose so you can direct the oil anywhere you want. No more spilling all over frame rails or exhaust headers! When you disconnect the female coupler, the pan coupler automatically closes and stops the flow of oil. 

This metric 22x1.5mm size includes a drain plug gasket and a protective cap to keep dirt out of the valve mechanism. Measures just 1" from the 1 1/4" (32mm) plug hex to the end of the cap. Flows approximately 0.68 GPM (10W30 oil at 170° F).  

Replacement parts also available separately:
Replacement Gasket for 22mm Drain Plug, Part No. 3228-375
Replacement Protective Cap for Quick-Drain Pan Coupler, Part No. 3228-361

wheelsmithy GRM+ Memberand SuperDork
8/10/19 2:27 p.m.

pipe thread and ball valve, cause beater?

Don't forget pipe dope.


Floating Doc
Floating Doc GRM+ Memberand SuperDork
8/10/19 7:05 p.m.

My friend suggested an oversized drain plug. He said that they will cut their own threads.

Also, he said some of them have an additional bolt in the center, so you don't have to remove it again.

I've found the oversize plugs, but no success looking for one with a smaller drain plug in the center.

oldopelguy UberDork
8/10/19 9:31 p.m.

Look for the kind you add to an automatic transmission that doesn't come with a drain plug; it will have the removable center bolt. 

I'd put the insert back in with whatever locktite you have to keep it from coming out again and add a fumoto myself, but if it's oversized enough already maybe tap it for pipe threads and install a radiator/air tank drain petcock. 

Floating Doc
Floating Doc GRM+ Memberand SuperDork
8/18/19 7:35 p.m.

Update: I bought single and double oversize plugs, with the piggyback plug (that's what they are called) in the center.

No go. When the Time-Sert backed out, it took the threads with it. It wasn't just stripped.

I popped in the Eco-plug magnetic plug. No leaks after about 30 minutes of running time and a couple of miles on the road.

This is with the engine running and warm.

Floating Doc
Floating Doc GRM+ Memberand SuperDork
8/24/19 11:20 a.m.

About 250 miles, still holding. I'll be towing with it again soon.

I know I should replace the pan, but if I do that I would want to replace everything between the drain plug and the hood.

ShawnG PowerDork
8/24/19 11:41 a.m.

Looks like just the right solution for this particular situation.


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