Moroso 35500 Ceramic Engine Seal - 1 Pint

I had, yes had an issue with my 79 Midget where steam would pour out of the exhaust when the engine was warm and idling. As I told my tale of woe about how I had to pull the head on the little beast to a mechanic at the fire dept he suggested I give Moroso Ceramic Seal a try. What was there to lose except $20? His two pieces of advice were to flush the living S**T out of the system and bypass the heater core as it can plug it up. Luckily for me I had an adapter on in the cooling system to hook up a garden hose and I went to town getting it flushed. Also lucky for me it had been recently done so the system was nice and clean to begin with.I replaced the coolant with water, got the motor to temp and carefully added the Ceramic Seal. Billows of steam filled my open garage while I was waiting for the car to come to temp before I added the ceramic seal. After I added it I drove away per the directions and drove the car up and down the street. As I came to a stop light 10 or 15 minutes later I noticed there was no steam coming out of the back of the car! I drove the car around for about 3 hours shopping, visiting and such. Not a wisp! Temperature stayed a bit above cold. Came home drained the coolant and let it sit for the day to "set" as per the directions.I still need to replace the coolant and start driving again but, so far. the stuff worked like a dream. I'll post updates. I suppose it could "let go" and I'm back to where I started.

I used Moroso Engine Seal in my 15 year old Subaru, to fix a head gasket leak - a common problem on these cars. Before purchasing, I asked for advice from a couple of mechanics, who told me to stay clear of these types of additives as they only offer a band-aid solution. What ultimately drove my decision to purchase this product and go against the advice I was given, was the favorable comments the product received on several automotive discussion forums as well as the cost of the repair, which would have been more than the value of the car. With over 220K on my engine, and facing a $1000 repair bill, it seemed I had little to lose, so I gave it a try. I followed the directions to the letter, and was pleased to discover that the engine was no longer leaking coolant internally. There was no sign of coolant in the oil, no bubbles in the coolant tank, no white smoke from the tailpipe, and no loss of coolant. Granted, it's only been one month, so only time will tell if this stuff holds up, but I am very pleased with the results so far. If you have an older car and have nothing to lose, give it a try.

Well, maybe not exactly, but after trying several other topline "guaranteed" block sealers on my 1983 Mercedes 300 Diesel--which was consuming water, running hot and smoking like a crop duster and obviously had a cracked block or blown head gasket--I ordered a couple of pints of this magic elixer, and followed directions to the letter. It requires a process of flushing every last molecule of antifreeze coolant out of the engine, so patience and determination are required on your part. After that lengthy flushing process and refilling with clear water, I put in the Moroso Ceramic Engine Seal and let the car idle for a half hour, reach operating temperature, then drove it around. Within a few miles, the smoke was gone, the temperature was holding at perfect level and upon my inspection, the water level had not dropped! A diesel is much harder to block-seal as they run enormously high compression as compared with a gasoline engine, and Moroso's product was the only one that could do the job! After 5,000 miles it's still running like new, so this is no "temporary" fix!

Did not work as well as a competitor’s offering of similar product.I’ve used this one twice. One time worked - next time did Not.

This stuff is magic! Had to leave it running past 15 minutes, then the white smoke started to slowly go away. It’s been a month now, did an oil change and no signs of water in the system AT ALL. Initially, the head gasket leak was pretty bad, so I was skeptical just like anyone else at first. $20 well spent compared to costly head gasket replacement for a V8.

Love this product. Had a cracked cylinder head and the coolant system was pressurizing and blowing out the coolant. Now temp is holding and coolant is maintaining

Moroso Ceramic Sealer has been around for years and still works great. If your car is losing coolant, drain all of the antifreeze from the system and replace with water and 1 bottle of Moroso Ceramic Sealer. Run the car for a couple days and the leak should be fixed. If it’s still losing coolant, add another bottle of Moroso Ceramic Sealer. Run for a couple more days and drain coolant system and replace with 50/50 antifreeze / water mix.

I used this as directed and flushed cooling system a few times. First bottle didn't work, and I repeated the idle sequence 4 times. So I added second bottle per instructions. Drip out of tail pipe finally stopped after 3rd idle period. But when I started it up in the morning, it spit out a glob of the sealer and then was leaking the same as before. So I tried the Steel Seal that has the guarantee, and also the $100 dollar price tag. I flushed the system very good again to make sure all the Moroso was washed out. Added fresh coolant mix (non dexcool), left thermostat out too. Steel Seal did not work either. At least they didn't charge me though, so all I lost was more time. So I'm gonna pull both heads off, replace the head gaskets, and also the valve seals while I'm at it......bummer!