Lower Intake Manifold??

I have a 98 S 10 Blazer. I had a coolant leak coming from the side of the Radiator, so I replaced it over the weekend. While I was at it, I replaced radiator hoses, thermostat, and the oil cooler lines going from the remote oil filter to the radiator. I flushed it all out and put it back together. Everything worked fine - for about 24 hours. Now I notice a new coolant leak coming from somewhere near the back of the engine. It isn't a large leak, but it is a steady drip. I checked my oil, and there is no coolant in the oil.

After all of the posts I've read on this, I'm assuming this is the Lower intake manifold gasket. My oil coolant lines are also leaking a little bit (that's why I did the ones that connect to the radiator when I did the radiator), but I put off the other set. I'm wondering about a couple of things...

1. Does this sound like a lower intake Gasket leak?

2. If it is - is there anything else I should replace while I have it open?

3. Will be any easier to do the other set of coolant lines while everything is apart for the Lower Intake?

Thanks for your help.

BTW - This site is a tremendous resource. It is a really great thing that everyone who is so knowledgeable about these vehicles takes the time to share the wealth and pass it on. THANK YOU!!

I have a 98 S 10 Blazer. I had a coolant leak coming from the side of the Radiator, so I replaced it over the weekend. While I was at it, I replaced radiator hoses, thermostat, and the oil cooler lines going from the remote oil filter to the radiator. I flushed it all out and put it back together. Everything worked fine - for about 24 hours. Now I notice a new coolant leak coming from somewhere near the back of the engine. It isn't a large leak, but it is a steady drip. I checked my oil, and there is no coolant in the oil.

After all of the posts I've read on this, I'm assuming this is the Lower intake manifold gasket. My oil coolant lines are also leaking a little bit (that's why I did the ones that connect to the radiator when I did the radiator), but I put off the other set. I'm wondering about a couple of things...

1. Does this sound like a lower intake Gasket leak?

2. If it is - is there anything else I should replace while I have it open?

3. Will be any easier to do the other set of coolant lines while everything is apart for the Lower Intake?

Thanks for your help.

BTW - This site is a tremendous resource. It is a really great thing that everyone who is so knowledgeable about these vehicles takes the time to share the wealth and pass it on. THANK YOU!!

Look it over and make sure it is not a heater hose connection or hose or something like that.
If it is the intake gasket run a search on it.
There should be some how to's posted on it.

MT-

Thanks for the reply. Heater hoses are dry as a bone, and I do not have any coolant leaking inside. The drip is coming from about where the firewall is, but not up high where the heater hoses are. It seems to be in about the center of that area, and it does drip on the exhaust. When all was said and done, the truck had been heated up to temperature, and when I parked it I had a puddle of coolant about 6" in diameter (I'm sure it would have been bigger as some undoubtedly burned off on the exhaust pipe).

I did run a search on it, and that's how I came up with the possible root of this problem.

MT-

Thanks for the reply. Heater hoses are dry as a bone, and I do not have any coolant leaking inside. The drip is coming from about where the firewall is, but not up high where the heater hoses are. It seems to be in about the center of that area, and it does drip on the exhaust. When all was said and done, the truck had been heated up to temperature, and when I parked it I had a puddle of coolant about 6" in diameter (I'm sure it would have been bigger as some undoubtedly burned off on the exhaust pipe).

I did run a search on it, and that's how I came up with the possible root of this problem.


http://www.automotiveforums.com/vbulletin/showthread.php?t=486234

I have a 98 S 10 Blazer. I had a coolant leak coming from the side of the Radiator, so I replaced it over the weekend. While I was at it, I replaced radiator hoses, thermostat, and the oil cooler lines going from the remote oil filter to the radiator. I flushed it all out and put it back together. Everything worked fine - for about 24 hours. Now I notice a new coolant leak coming from somewhere near the back of the engine. It isn't a large leak, but it is a steady drip. I checked my oil, and there is no coolant in the oil.

After all of the posts I've read on this, I'm assuming this is the Lower intake manifold gasket. My oil coolant lines are also leaking a little bit (that's why I did the ones that connect to the radiator when I did the radiator), but I put off the other set. I'm wondering about a couple of things...

1. Does this sound like a lower intake Gasket leak?

2. If it is - is there anything else I should replace while I have it open?

3. Will be any easier to do the other set of coolant lines while everything is apart for the Lower Intake?

Thanks for your help.

BTW - This site is a tremendous resource. It is a really great thing that everyone who is so knowledgeable about these vehicles takes the time to share the wealth and pass it on. THANK YOU!!


Here is a lot of good info for 5.7 but will reto fit to a 4.3.:grinyes: :grinno:
http://www.automotiveforums.com/vbulletin/showthread.php?t=338757

Good Luck

I saw this. Thanks. I also saw another one on this job. I don't recall who wrote this, and I didn't bookmark the forum, but he wrote out a very detailed description. I copied that forum and edited it a little (so that it was easier to read) and saved it. It matched nicely with the photos from the post you reference. I will post it here if you think it might be helpful to others...



Any Idea if those Oil Coolant lines from the Remote filter to the block will be easier to change when I have this all apart. It looks like this stuff is all above where those lines run. Is it easier if I have some more room from above, though?

I saw this. Thanks. I also saw another one on this job. I don't recall who wrote this, and I didn't bookmark the forum, but he wrote out a very detailed description. I copied that forum and edited it a little (so that it was easier to read) and saved it. It matched nicely with the photos from the post you reference. I will post it here if you think it might be helpful to others...



Any Idea if those Oil Coolant lines from the Remote filter to the block will be easier to change when I have this all apart. It looks like this stuff is all above where those lines run. Is it easier if I have some more room from above, though?

You can post the link. It may help someone else.
There is a lot of good how to's but sometimes hard to find.
I had to do some looking to find what I did.:grinyes: :grinno: :lol:
I think Girlbear done her intake and may have posted some info on it to.
Also a good repair manual or a all data sub will help you threw it.
http://www.alldata.com/products/diy/index.html
Make sure you get it all torqued down right.

Other things to check would be fuel pressure regulator and dist cap and rotor and heater hoses and heater hose quick coupler if it has the old pot metal one replace it with a good steel coupler.
And when you are done with it check the camshaft retard setting on a scanner.
Also change the oil and filter.

Having the intake off will not help much on the oil lines.
But if they are leaking they should be replaced.

Good Luck MT

Take some more time to find out exactly where the coolant is leaking from. The freeze plugs are also a common leak point.

Where are the freeze plugs, and how easy are they to get at/ change?

Perhaps this will help. Here is a picture of where the leak ends up. This is taken from the drivers side looking up at the bottom of the engine.

http://i140.photobucket.com/albums/r38/yeags01/IMG_5837.jpg

Intake manifold for sure.

Flushing these things often causes leaks in other places - the nature of the cooling system design along with Dex cool and air. Lower intake can seep up between the valve cover and intake and then run down the back or front based on parking angle. After it heats up use a good flashlight and look along there for leakage. Look at the heater hoses to intake connections too. Also the rear of the lower intake can leak as its only sealer (RTV) along the entire rear section and on each side there is a water passage in the block thst is capped off by the intake (block been aroynd for some time with diff intake). Front sides are the used passages that cool the intake now and often leak down the front of the lower to block and often are mistaken as water pump leaking. Almost forgot if the coolant is dripping down from the silver AC heat shield to the starter then down the back could be a heater core but you usually smell it in the ducts with heat or AC on.

Isn't the '98 a plastic intake base? Either way, you might be looking at this:

http://72.19.213.157/files/IntakeLeak03.jpg

Thank you all for your help and advice. I'll get it done this weekend.