Please tell me I'm not SOL -- coolant leak from high on back of engine

[strad]

99 tahoe, 5.7 Vortec. I noticed an orange drip from the left side of the transmission bell housing (at the very front where it attaches to the engine). This just started this morning. I cannot see anything from on top, but best I can tell from below, which isn't well, it does not appear to be coming from the left side head gasket. I can sort of see that area from below. What else is up there where coolant could be coming from? I'm assuming that whatever is leaking is left of the centerline of the top of the bell housing, since it is not running down the other side at all.

As far as I know, the engine compartment is completely stock, so assume stock coolant hose routings.

 

[inthechateau]

Intake manifold gasket is your dilemma. A very common issue on the 5.7 engines. Not an difficult fix, just time consuming.

 

[strad]

ok based on that information, I went and looked again. There appears to be evidence of liquid running down the back of the head from where the intake manifold attaches. This would be directly below where the fuel feed and return lines go through a bracket at the back of the manifold. I can see it from below, but not from above. I did stick a white paper towel back there and came away with a spot of orange after rubbing that area of the head.

So my next question is, does that sound like a logical location for coolant to be coming from, if the intake manifold gasket was the source of the leak? In other words I have no idea what path coolant takes inside there lol.

If I do have to do the gasket, does the distributor need to be removed? I can't tell for sure. It looks like the intake manifold bends around the distributor so that it (the manifold) can be removed without disturbing the timing. Is that correct?

 

[retorq]

No the distributor needs to come out.

 

[livingez_123]

intake coolant leak with the 5.7 is very common.

 

[strad]

Thanks. Picking up the gasket kit this week. This is going to turn into a while I'm in there afair. I just know it lol. I've done a lot of this sort of work on my bimmers, but not gotten very deep into a small block before. And this vehicle is a dd, which adds to my pressure to not have issues with the procedure. I'm going to have my father in law next to me while I do it. He's quite experienced.

 

[livingez_123]

just clean the top end as good as you can before tear down. The intake is a fairly easy job. roll the engine to TDC before you pull the distributor and mark on the cap where the rotor is pointing. This will make reassembly a lot easier.

 

[_Dylan_]

The gaskets actually break at the front on the intake at the crossover, then leak down the sides to the back of the block.

Get the fel-pro MS98000T gasket set.

Yes the distributor must be removed. Just mark on the firewall the direction the rotor is pointed in, so when you drop it back in it will start right up.

But, keep a close eye on the oil dipstick if you're going to keep driving it. Coolant leaking in the oil is not good.

Here is a good link with some pictures:
http://www.market-place.com/intake/

IIRC, you will only need some basic sockets and wrenches, gasket scraper/razorblade, and a torx screwdriver for the dizzy cap.

The fel pro kit will come with upper and lower gaskets, I only chose to change the lower ones. I decided to just leave the intake in only piece rather than split it apart and change the upper gasket.

Also, It could be that the coolant quick disconnect on the passenger side of the intake towards the front is leaking. If it is, good luck. Those things tend to break off and require drilling and tapping to fit a new disconnect. Mine wasn't leaking, so elected to be as careful as possible and remove the intake with that coolant hose still attached. So far so good, no leaks from the original disconnect or the new lower intake gaskets.

 

[strad]

Well I just pulled the oil cap and also checked the dipstick. There may possibly be some residue on the cap, but the oil on the dipstick is clean. And it smells and feels like oil.

Edit: the "quick release" you speak of definitely has residue/corrosion on it. It's not wet, and no evidence of moisture. But you're saying this could ruin my day?

 

[_Dylan_]

yeah, try not to break it when you take the intake off.

 

[Goodinblack]

Been there.

Done that.

2X.

1996 Tahoe.

2001 Express G3500.

I did the Van myself. Caught it before it totally ruined the engine. Oil and antifreeze cause a caustic mixture that eats the mains. You are lucky if it leaks outward. Inward it mixes into the oil and eats at the bearings.

Put the engine at TDC pull the distributor.
Also you need new o rings at the fuel rail quick connects. AC compressor can be unbolted and moved off to the left. Up and over. No need to discharge the refrigerant.

PS steering pump and bracket assembly may need to be loosened and pulled forward as well.

Be careful also when removing the throttle linkage at the Throttle body. Plastic crap breaks.

Right side valve cover also may need removal.

 

[strad]

Ok I have the fel pro 98000t gasket set and an extra vcg. Also got a Tstat. The Tstat works fine, but while I'm in there. . . Also there will be a lot of cleaning lol.

Btw what is the lifespan of cap and rotor? I know mine have about 46k on them.

 

[strad]

Ok repair is done. Very grateful to my father in law for his help. He came of age working on small blocks back in the sixties. The previous gasket replacement was done in 2011, about 3k miles before I bought the truck. So the gaskets had 37k miles on them. They were the old style -- no metal backing. And they were both distorted and damaged in a few places. I'm guessing that it was the left one that was leaking, and near the front of the engine, since I had fluid coming out both the front and the rear on that side. The intake manifold bolts appeared to have been overtightened by the last guy in there. Also the distributor housing is somewhat broken where the cap attaches to it -- I'm told that is a common occurrence. Still annoying though. The thermostat bypass hose wouldn't seal properly against the manifold fitting so we had to get a new one. Also replaced the cap and rotor, and the thermostat. And we busted that little plastic emissions line that runs from by the secondary air pump over the top of the motor and thence to the firewall next to the receiver dryer. Auto parts store had that in three foot lengths, so we reused all the fittings and put new line in. Seems that we have stopped the coolant loss.