brentw

It started with noisy lifters. I removed intake, replaced lifters, reinstalled everything. lifters are now quite. found lots of water in oil. Found out I dumped water in oil when I pulled intake. (new to this im learning as I go) I pulled intake back off, replaced gasket, drained/replaced oil(10w30) fired car up sounds great. Drove car around to get it nice and warm. Now oil psi is low at idle when warm. drained oil, put in 20w50. seemed to help a little, but still to low at idle when warm(about 5 to 10 psi). When I pull the dip stick it looks like it has some water mixed in, not really milky but, just weird. I hooked up a psi tester to the radiator can, and pressurized it to 12 psi. it leaked down within 1 to 2 mins. I can hear a dripping sound in the can when pressurized. did I screw up the intake install or what? Please help thanks so much Brent. P.S I forgot to say its a 1971 corvette with numbers matching 350. 270 hp

Roco71

When installing the intake did you use any (small amount) of silicone around the water ports? And any sealant on the bolts to keep oil from wicking up them?

7T1vette

Hard to tell where your leak is from this darn computer....

But, you don't want to mix water and oil IF the water has glycol antifreeze in it. Glycol and oil together make an emulsion...something like tapioca pudding. And, it will plug up everything and be really difficult to clean out of the engine passages.

So, you need to find the leak. If it is inside the engine (intake gasket, for example), tear it down as far as you need and fix it SOON. But, remember, it could be just a coincidence that you noticed this leak at the same time as the intake removal. So, it could be a head gasket giving up somewhere near a water passage.

Don't know how to best advise you from my keyboard; diagnostics on your end are required. But, the most likely leak source IS at an intake manifold gasket--just because you have recently been in there.

billla

Good on you for getting hands-on with your 'Vette...but I would post on your regional board to see if an experienced local Forum member is willing to come out and help.

It's not clear how long you ran or drove the car with water in the oil either time - but if the low oil pressure coincides with the lifter change, it's a concern. Bearings don't hold up long with water in the oil.

Also a bit concerned with new lifters on an old flat-tappet cam - this marriage also doesn't usually work out well.

Get some local, experienced help to sort this one out.

brentw

I did use sealant around water ports on intake. and used sealant on the bolts the first time, however the second time I did not use on bolts because they seemed to have so much on them from before.

AZDoug

It is hard to screw up an intake install, but i suppose it could be done.

Did you make sure all you gasket surfaces were scraped squeaky clean?

Did you torque the bolts in the correct sequence?

Did the bolts all go right in, or did you ahve to work to get them in due to a misalignment caused by head surfacing? If the heads have been surfaced or the block decked, often the end gaskets shouldn't be used and an RTV silicone bead used in stead

Noisy lifters was probably an adjustment issue, not anything that needed replacing. Typically, if lifters are bad, the cam is bad also.

Doug

billla

All good.

Intake R&R isn't all that difficult to screw up, especially in the car - getting the right amount of sealant on the front/rear cam valley and around the water ports, and then setting it in just so is easy for a pro, but not so much for someone doing it for the first time.

7T1vette

One thing that IS important is the type of sealant that you use. Regular silicone sealants should never be used on an auto engine, IMO. RTV Ultra Black silicone is the only one made to work with water, oil, etc. It does a good job for valley ends sealing and oil pan surface junctions. If you used the RTV, that should not be your problem; otherwise, who knows?

I use nothing but Fel-Pro gaskets. The 'hard' gaskets, like heads, intakes and exhaust manifolds, should not get any sealant except for 'junctions'. For composition [cork/synthetic rubber] gaskets, I might use Permatex #2 sealant which is non-hardening. It seals well, but you can still get things to separate if you need to remove a cover, etc.

No other sealants are needed; nor should they be used, IMO.

DUB

with the addition of using the AC Delco engine sealant in a tube. A light gray color sealant. This is some seriously "wicked" stuff that blows away the Ultra Black"...because I use the Ultra Black a lot also....and LOVE IT...but if I am doing an oil pan while the engine is in the car...I will reach for the AC Delco sealant because it is thick and tacky enough to hold all the gaskets in place and allow me to install the pan without any fear of gaskets dropping off. A super thin coat of the AC Delco stuff will allow a gasket to stick to whatever you are putting it on...that is for sure. Kinda pricey though.

Expect (with all due respect) I prefer to use GM intake and head gaskets. I like the material much better than the blue stuff on a Fel-Pro gasket. I pull off engine with Fel-pro gaskets and nothing is left behind in most of all the cases...BUT the GM intake gaskets stick and seal really good...and will often times get destroyed when it is removed...and this is without any added sealants on them.

DUB