---
product_id: 82132425
title: "K-Seal Ultimate"
brand: "k-seal"
price: "€ 50.87"
currency: EUR
in_stock: null
reviews_count: 13
category: "K Seal"
url: https://www.desertcart.fi/products/82132425-k-seal-ultimate
store_origin: FI
region: Finland
---

# Instant Pour & Go application Seals leaks up to 0.64mm 33% more sealing power K-Seal Ultimate

**Brand:** k-seal
**Price:** € 50.87
**Availability:** ❌ Out of Stock

## Summary

> 🛠️ Fix it once, drive forever — the ultimate head gasket hero!

## Quick Answers

- **What is this?** K-Seal Ultimate by k-seal
- **How much does it cost?** € 50.87 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.fi](https://www.desertcart.fi/products/82132425-k-seal-ultimate)

## Best For

- k-seal enthusiasts

## Why This Product

- Trusted k-seal brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Effortless Application:** No draining or flushing needed—just shake, pour, and drive on.
- • **One-Step Leak Lockdown:** Ceramic micro-fibres seal cracks and holes up to 0.64mm without engine downtime.
- • **Permanent Engine Savior:** Advanced formula delivers 33% more sealing power than standard sealers for a lifetime fix.
- • **Universal Compatibility:** Works seamlessly with all coolant types and engine materials, from cars to heavy machinery.
- • **Mechanic-Trusted Reliability:** Independently tested and ASTM D3147 certified, trusted by professionals worldwide.

## Overview

K-Seal ST3501 is a professional-grade, permanent head gasket and block sealer with 33% enhanced sealing power. It effortlessly seals leaks up to 0.64mm using ceramic micro-fibres, requires no engine draining, and is compatible with all coolant types and engine materials. Trusted by mechanics and independently verified to ASTM D3147 standards, it offers a cost-effective, long-lasting solution to blown head gaskets, cracked heads, and porous blocks—making expensive repairs a thing of the past.

## Description

Introducing the K-Seal ST3501 Pour and Go Permanent Head Gasket and Block Repair, a revolutionary solution for head gasket leaks. This 16 fl. oz. bottle of head gasket stop leak is your ultimate solution to costly and time-consuming head gasket repairs. With K-Seal, you have the best head gasket sealer at your disposal, designed to provide a permanent fix for blown head gaskets, cracked heads, and blocks. No need for a professional mechanic – this is a universal fit product that anyone can use. The K-Seal ST3501 is not just a head gasket leak sealer; it doubles as a block sealer for engines, effectively sealing any coolant leaks. It guarantees a lifetime of reliable performance. What sets K-Seal apart is the simplicity of its application. Just Pour & Go – there's absolutely no need for expensive head gasket repairs. As a head gasket fix, it's designed for ease of use. No need for a head gasket test kit or a head gasket repair kit. This product is a coolant leak sealer and head gasket repair in one, eliminating the need for a separate head gasket test. K-Seal is scientifically tested, and the only product to have been successfully tried by Brighton University, meeting the demands of ASTM D3147. If you're dealing with a head leak, antifreeze coolant stop leak, or need a head gasket additive, choose K-Seal. It's the safe and easy way to fix a coolant leak, and is ideal for use as a head seal, head gasket seal, and head gasket spray. Trust K-Seal for your head gasket repair needs and experience the ultimate in head gasket solutions.

Review: It actually works very well - I have a 2012 Toyota Prius type v they're generation known to have head gasket issues over time. Well my time had come last winter Winter of 2024 and I was deciding whether to put new engine in it though I did not have the money and I called a repair shop in town called engine and transmission exchange and told him I dilemma. Well to my surprise The gentleman behind a counter felt my problem and told me try this he had a guy who delivered parts who had a old Chevy van that had the same head gasket issue. He gave it a shot because one of his mechanics told me to try it what's the worst that could happen. By God it worked that man has been driving that same vehicle for 5 years now so I gave it a shot. It's a year later I've had no head gasket issues whatsoever no overheating no loss of fluids since that time I put it in. Heck of a lot cheaper than the engine. A $23 bill is a heck of a lot cheaper than a 5 to $6,000 engine replacement.
Review: Improved my old car's performance greatly! - Have a 2004 Ford Escape with about 200,000 miles. Started getting a check engine light; misfire on #1 at startup and very rough idling every time I started the (cold) engine in the morning until it warmed up. Tried the usual; plugs and ignition coils but no help. Noticed I was using water but no sign of a leak. Finally suspected that I had a blown head gasket around #1 cylinder. Read good reviews about K-Seal so thought I'd give it a try and poured a 16oz bottle in. Drove it around for about 20 miles then parked it till next morning. Started it up and no check engine light and the idling was much improved (but not great)! I left the K-seal in and now, about 3 weeks later, have not had a check engine light again and the idling has improved steadily until I can say it is now very smooth at startup and when stopped in traffic. I think by leaving the K-Seal in that the gasket leak has steadily improved and so has the engine performance. Thank you K-Seal!

## Features

- PERMANENT REPAIR: Our advanced formula with 33% more sealing power than regular K-Seal, ensures a long-lasting, permanent seal for challenging leaks. Permanently fixes blown head gaskets, cracked heads & porous engine blocks in cars
- STOP HOLES & CRACKS: With just 1 step our unique formula with ceramic micro-fibres, will permanently seal leaks up to 0.64mm in size, without any adverse impact on the engine
- EASY TO USE: It requires no draining or flushing; just shake, pour & go - shake the bottle, add the fluid wherever you top up your coolant & run your engine as normal. For larger engines (HGV's / Plant) use 2 bottles
- VERSATILE COMPATIBILITY: Works with all types of coolant & compatible with a wide range of vehicle engine materials & heavy duty machinery. A permanent fix for the lifetime of the engine
- PROFESSIONAL-GRADE RELIABILITY: Trusted by mechanics, our sealer treatment delivers a durable & long-lasting repair. A cost-effective head gasket & block repair, enhancing the performance of your vehicle’s cooling system. We've sold millions worldwide & are independently verified by university testing to meet ASTM D3147.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00QYZIVA6 |
| Best Sellers Rank | #4,913 in Automotive ( See Top 100 in Automotive ) #2 in Cooling System Additives |
| Brand | K-Seal |
| Customer Reviews | 4.1 4.1 out of 5 stars (1,993) |
| Date First Available | November 14, 2014 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 1 pounds |
| Item model number | KSLST3501 |
| Manufacturer | Solv-Tec |
| Manufacturer Part Number | KSLST3501 |
| Model | ST3501 |
| Product Dimensions | 2.5 x 2.5 x 8 inches |

## Images

![K-Seal Ultimate - Image 1](https://m.media-amazon.com/images/I/61ESypiDG+L.jpg)

## Questions & Answers

**Q: Is it okay to continue to idle the car with engine and brake lights on with liquid coming out of radiator? It says to idle for 20 minutes**
A: The system should be sealed as the product circulates though it for the 20 minutes.

**Q: Does it  use Sodium Silicate?**
A: Nowhere on the bottle does it say sodium silicate.

**Q: I have a 1999 ford ranger. running fine now but it is getting older. can i use this as a preventative? or do i need to wait for a problem to show up?**
A: The way K seal works is by seeking out leaks in a pressurized system. I feel you or best bet would be to wait until you know your leaking coolant. I use this in a truck about 7 months ago and I still have no problems with the truck. Work very well

**Q: can i make a 100 make a 100 mile trip 10 minuets after i put the k-seal in...**
A: Yes! It does it's magic within 10 minutes. Just don't drive it too hard for about 20 minutes. Drive smooth. Highway driving or a good road with a consistent speed is best. After 20 minutes, you are all good!

## Customer Reviews

### ⭐⭐⭐⭐⭐ It actually works very well
*by S***N on January 2, 2026*

I have a 2012 Toyota Prius type v they're generation known to have head gasket issues over time. Well my time had come last winter Winter of 2024 and I was deciding whether to put new engine in it though I did not have the money and I called a repair shop in town called engine and transmission exchange and told him I dilemma. Well to my surprise The gentleman behind a counter felt my problem and told me try this he had a guy who delivered parts who had a old Chevy van that had the same head gasket issue. He gave it a shot because one of his mechanics told me to try it what's the worst that could happen. By God it worked that man has been driving that same vehicle for 5 years now so I gave it a shot. It's a year later I've had no head gasket issues whatsoever no overheating no loss of fluids since that time I put it in. Heck of a lot cheaper than the engine. A $23 bill is a heck of a lot cheaper than a 5 to $6,000 engine replacement.

### ⭐⭐⭐⭐⭐ Improved my old car's performance greatly!
*by T***S on June 25, 2025*

Have a 2004 Ford Escape with about 200,000 miles. Started getting a check engine light; misfire on #1 at startup and very rough idling every time I started the (cold) engine in the morning until it warmed up. Tried the usual; plugs and ignition coils but no help. Noticed I was using water but no sign of a leak. Finally suspected that I had a blown head gasket around #1 cylinder. Read good reviews about K-Seal so thought I'd give it a try and poured a 16oz bottle in. Drove it around for about 20 miles then parked it till next morning. Started it up and no check engine light and the idling was much improved (but not great)! I left the K-seal in and now, about 3 weeks later, have not had a check engine light again and the idling has improved steadily until I can say it is now very smooth at startup and when stopped in traffic. I think by leaving the K-Seal in that the gasket leak has steadily improved and so has the engine performance. Thank you K-Seal!

### ⭐⭐⭐⭐⭐ Not going to lie, I did not really expect this to actually work.
*by S***O on January 25, 2025*

Jeep Wrangler 4.0 Inline 6. Had an issue with a piston and suffered a catastrophic failure. Disassembled engine, and replaced piston, then reassembled with a fresh head gasket. Did not plane block or head, just put it back together. Engine ran fine, but I noticed lack of coolant system pressurizing, and I was refilling the radiator daily. I found a pressure leak near number 1 cylinder, which was causing significant coolant loss when engine was operating. My head was either damaged or I nicked the gasket when putting it back together by myself. Which is possible, that head is heavy and awkward. Anyway, after a lot of reviews and research, I selected K-seal. I followed instructions and added it directly to radiator. It has small copper looking flakes in it, and at first I thought it was a waste of time, because after pouring it in, and going for a drive I saw the same small flakes on the inner fender where the steam from the leak was coming from. Then after a few more days, I noticed that my cooling system was fully pressurized when hot, and the coolant was not disappearing every day. It has been about three weeks and several hundred miles, and it is solid as a rock. No coolant leak, smell or refill needed. Very impressed, this really worked.

## Frequently Bought Together

- K-Seal ST3501 Pour and Go Head Gasket Sealer, 16oz, Permanent Repair for Blown Head Gaskets, Cracked Heads and Blocks
- K-Seal ST5501 Multi-Purpose One Step Permanent Coolant Leak Repair, 8oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required
- K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Permanent Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

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*Product available on Desertcart Finland*
*Store origin: FI*
*Last updated: 2026-02-17*