The upper intake manifold may develop an internal coolant leak causing one or more cylinders to fill with coolant. This can cause the engine to "hydro-lock" and not turn over. Removing the spark plugs will allow the engine to turn over pushing the coolant out of the spark plug holes. Replacing the upper intake plenum and gasket is commonly required to correct this condition.
The engine can be very difficult to start after this problem has been repaired, it can be helpful to clear as much of the coolant from the intake manifold and cylinders as possible before reassembling the intake manifold.
Average mileage: 468,823 (16,000–10,098,163)
42 people reported this problem
coolant leak at upper intake. common problem with the 3800 engine. had repaired along with new hoses. total cost $785. Ouch) i dont know how gm avoided not recalling this problem. there are ten's of thousands of people that had this happen to them too.
my car is using coolant its going through intake and out into the cylinders and being pushed out exhaust my buick under a load going uphill starts missing because of the coolant leaking into the intake manifold gas chambers causing multiple miss fires
I have a 1997 model and just had the plenum which is the intake replaced. It wouldn't start and i told the mechanic there was antifreeze in the black tube going to the air filter and he said it was the intake. Its made of plastic and there is a metal pipe that exhaust heat goes through and melts a hole in the intake that allows coolant to enter the top of the engine. The part is around $130.00 or so but the total repair totalled $530.00. There was no knocking from the hydro-lock so we decided to fix it. Hope this was helpful..
Heater blew cold, engine overheated. Next morn low on coolant. Filled and started. It blew it out exaust then shut down and wont start.
Coolant in all 6 cylinders
leaking coolant, changed intake gasket
Was traveling at freeway speeds when the ck engine light started to flash. Water temp gauge started to climb but never got close to the red line. Engine started to loose power and run rough. Made it to a parking lot and shut it down. I let the engine cool before opening the radiator cap. The coolent was non existant. Tried to start it but was hydro locked. Most of the cylinders had antifreeze in them. Replaced the intake, plugs and sirpentine belt.
I have a 98 buick park avenue that had a hydrolock, the engine light came on and off and the motor lost power, i pulled over, opened the hood and the radiator hoses were all collapsed, had to replace the seals on the head, it was over a $1000 to repair, I still am loosing coolant from the over flow
tech was doing a major tune up felt water and said the intake was leaking and needed to be replaced before coolant got in to cylinders he fixed it and no more coolant loss.
Overheated and lost coolant. Repair shop had it for 10 days and stated the car never over heated when he took it out driving. He said he put it on the lifts and couldn't find anything again. 2 days later the car had a smell and started smoking. I took it back and they said the intakes were bad from wear and tear?
it wont start due too the problem of 1 or more of the cylinders filling with water. after putting a new radiator in. this problem came up. so guess to the scrap yard. t
Intermittent service engine light, need to top off coolant and oil between regular oil changes, check gas cap notice, rough start when cold , missing under load (slight incline with 4 persons in car. These symptoms are all intermittent but regularly occurring & makes the thought of taking a long trip worrisome & risky, being caught at mercy of mechanic that one does not know with downtime.
Replaced all gasket intake upper and lower
Just bought 1999 Lesabre Limited for 500$. Car only has 80,561 miles on it, and is in excellent condition. Has the 3800 series 2 engine. Guy said head gasket was blown so I replaced the head gaskets, had a head job done with new valve seals ect..., replaced upper and lower intake gaskets, plentum gasket, thermostat, timing chain, oil pan gasket, basically every seal and gasket has been replaced. Total cost was about 700$ for everything. Me and a friend did all the work so it saved me a lot of money. Motor ran very smooth like new when it was finished. Drove it about 70 miles and then engine missing out and then hydro-lock. Turns out that the upper intake has this same common problem as the rest of these people's engines. There was coolant in 3 of the cylinders when we tore engine apart the first time to replace everything. Turns out, this was the problem all along, the head gaskets were never blown. I agree with a previous comment that this should have been a GM recall. Well, at least the engine is good for another 100,000 miles now.
While my coolant system starting with the waterpump and then the radiator and then I was driving it and it ran hot and shut off and then. I got it towed. To my shop and next it like the coolant was flowing and then the coolant mixed with oil
starter tried to turn over but it was not ,changed starter same thing , cable , nothing put breaker bar on harmonic and turned till it got real tight pulled one plug and pulled harder and it turned over , turned key and it cranked ok,sounds like it is out of time now no start, sugest not changing the starter try every thing else first
My gasket was deteriorated, replaced it & plenum - problem solved!
Indications were adding a quart of oil between changes, adding coolant at every 1500 miles, missing/rough engine on cold start, missing noted under load, intermittant service engine light, milky gunk on dip stick. Cost was $465.00 at trusted private garage/mechanic.
filled collant tank up. ran engine to warmup. waited a few minites, restarted, blew noise cone off of starter. replace starter, dry out sparkplugs, replace uppermanifold.